U.S. patent number 3,854,366 [Application Number 05/464,363] was granted by the patent office on 1974-12-17 for automatic arpeggio.
This patent grant is currently assigned to Nippon Gakki Seizo Kabushiki Kaisha. Invention is credited to Ralph Deutsch.
United States Patent |
3,854,366 |
Deutsch |
December 17, 1974 |
AUTOMATIC ARPEGGIO
Abstract
Automatic arpeggio and glissando effects are produced in a
keyboard electronic musical instrument by entering note-selection
signals in a single octave note storage register. The note storage
register is acanned sequentially and repetitively at high speed
under control of a note scan shift register. Scanning is suspended
for tone generation each time a note-selection signal is shifted An
octave counter, incremented at the completion of each scan of the
note storage register, specifies the octave of the each generated
tone. Different arpeggio modes are implemented, including a "harp"
mode in which the octave backtracks each time a certain number of
tones have been generated. In a glissando implementation, all notes
of the chromatic or diatonic scale are generated in sequence,
beginning and ending at notes selected on the instrument keyboard.
Sequential tone generation is accomplished with circuitry like that
for argpeggio. The glissando range is established by scanning the
keyboard with a shift register containing a single 1 bit shift in
unison with scanning of the note storage register and octave
counter. Tone production is inhibited until the first depressed key
is detected. Thereafter notes of the selected scale are generated
in sequence until detection of the depressed key signifying the end
of the glissando range. In a strum mode, the glissando is produced
repetitively.
Inventors: |
Deutsch; Ralph (Sherman Oaks,
CA) |
Assignee: |
Nippon Gakki Seizo Kabushiki
Kaisha (Shizuoka-ken, JA)
|
Family
ID: |
23843648 |
Appl.
No.: |
05/464,363 |
Filed: |
April 26, 1974 |
Current U.S.
Class: |
84/655;
84/DIG.22; 84/663; 984/388; 84/662; 84/666; 984/341 |
Current CPC
Class: |
G10H
7/00 (20130101); G10H 1/26 (20130101); G10H
2210/221 (20130101); Y10S 84/22 (20130101); G10H
2210/185 (20130101) |
Current International
Class: |
G10H
7/00 (20060101); G10H 1/26 (20060101); G10h
001/00 (); G10h 005/00 () |
Field of
Search: |
;84/1.01,1.03,1.13,1.17,1.24,1.26,DIG.22 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Wilkinson; Richard B.
Assistant Examiner: Witkowski; Stanley J.
Attorney, Agent or Firm: Silber; Howard A.
Claims
I claim:
1. Apparatus, useful in conjunction with an electronic musical
instrument, for producing arpeggio and like effects,
comprising:
a note storage device containing note-selection signals indicative
of an arpeggio chord,
note scanning means for repetitively sequentially scanning said
note storage device, said scanning being suspended to permit tone
production each time that a note-selection signal is detected in a
scanned location of said note storage device, and
play direction means, operative upon detection of a note-selection
signal, for directing said musical instrument to produce a tone,
the note and octave of said tone being established respectively by
the scanned location containing said detecting note-selection
signal and by the number of times said storage device has been
scanned repetitively.
2. Apparatus according to claim 1 wherein said note storage device
is a single octave in length, and further comprising;
keyboard switch means facilitating selection of said arpeggio chord
in any octave of a keyboard of said musical instrument, and
start means for causing entry into said single octave note storage
device of note-selection signals corresponding to said keyboard
selected arpeggio chord and for initiating said scanning to start
arpeggio production.
3. Apparatus according to claim 2 wherein said notestorage device
comprises a storage register having 12 storage locations
corresponding to the 12 notes of the chromatic scale, and wherein
said keyboard switch means comprises a set of contacts on said
keyboard connected so that the closure of a key contact for a
particular note in any octave will result in entry of a signal into
that single storage location corresponding to said particular
note.
4. Apparatus according to claim 1 wherein said note scanning means
includes an octave counter the contents of which designates the
octave of said produced tone, the contents of said octave counter
being set to the first octave of the produced arpeggio upon
imitation of scanning, the contents of said octave counter being
advanced by one upon completion of each sequential scanning of said
note storage device.
5. Apparatus according to claim 4 wherein said note scanning means
further includes;
a note scanning device having 12 positions corresponding
respectively to the 12 storage locations in said note storage
device,
shift means, including a scan rate clock, for actuating said twelve
positions sequentially, and
detector means for detecting the presence of a note-selection
signal in the signal storage location corresponding to the actuated
position of said note scanning device.
6. Apparatus according to claim 5 further comprising;
up-down arpeggio control means for selectively enabling up arpeggio
or down arpeggio, said control means initially setting said note
scanning device and said octave counter to their lowest position
and enabling each to be incremented during said scanning to produce
up arpeggio, said control means initially setting said note
scanning device and said octave counter to their highest position
and enabling each to be decremented during said scanning to produce
down arpeggio.
7. Apparatus according to claim 6 wherein said arpeggio control
means successively, alternately enables up and down arpeggio,
together with start-stop switch means for initiating and
terminating the resultant continuous up-down arpeggio.
8. Apparatus according to claim 5 further comprising;
note duration timing means, operative upon detection of a
note-selection signal by said detector means, for inhibiting
sequential actuation of said scanning device positions for a preset
time interval during which said play direction means directs tone
production.
9. Apparatus according to claim 5 further comprising;
attack/decay control means, operative upon detection of a
note-selection signal by said detector means, for sequentially
providing a set of attack/decay scale factors for use by said
musical instrument to establish the envelope of the produced tone
corresponding to said note-selection signal.
10. Apparatus according to claim 9 wherein said shift means
sequentially actuates said twelve positions at a high speed
established by said scan rate clock, together with means for
suspending said sequential actuation for a note production interval
beginning with detection of a note-selection signal and ending when
said set of attack/decay factors has been provided to said musical
instrument.
11. Apparatus according to claim 4 for producing arpeggio in the
harp mode, comprising:
harp counter means, responsive to said play direction means for
counting the number of notes in one octave of said arpeggio chord
and for establishing a "harp count" related thereto,
produced tone counting means for counting the number of tones
sequentially directed for production by said play direction means,
and
decrementing means for decrementing said octave counter each time
that the number of sequentially produced tones counted by said
produced tone counting means equals said harp count, and for
resetting said produced tone counting means.
12. Apparatus according to claim 1 for producing glissando,
comprising;
scale means for entering into said note storage device
note-selection signals indicative of notes of a scale, and
glissando range control means, cooperating with said play direction
means, for enabling sequential tone production only of notes within
a selected glissando range.
13. Apparatus according to claim 12 for producing strum effects,
comprising:
restart means, cooperating with said glissando range control means,
for restarting said apparatus to repeat operation after completion
of enabled tone production within said selected glissando
range.
14. Apparatus for producing arpeggio automatically in a keyboard
electronic musical instrument, comprising:
note storage means, having a number of storage locations
corresponding to the number of notes in a single octave of a
musical scale, for storing signals in locations corresponding to
selected notes independent of octave,
scanning means for sequentially scanning all of said storage
locations at rapid rate and for suspending said scanning for a time
period permitting tone generation each time a stored
note-indicating signal is detected in a scanned storage location,
and
repetitive scan control means, operative upon each completion of
sequential scanning of said storage locations and including an
octave counter incremented at each such completion, for causing
said scanning means again to scan said storage locations, the
detected note-indicating signal and the contents of said octave
counter together specifying the note to be generated by said
instrument during each respective tone generation time period, the
repetitively generated notes thus constituting an arpeggio.
15. Apparatus according to claim 14 wherein said note storage means
comprises a note storage register having twelve storage locations,
and wherein said scanning means comprises;
a note scan shift register having twelve positions,
a scan clock providing pulses at high speed,
a logic gate connected, when enabled, to supply pulses from said
scan clock to the shift input of said note scan register,
load means for loading a single 1 bit into one position of said
note scan shift register and for enabling said logic gate, and
note duration timing means, operative upon detection of a
note-indicating signal in the storage location corresponding to the
shift register position currently containing the signal 1 bit, for
disabling said logic gate and hereby suspending said scanning
during said tone generation time period.
16. Apparatus according to claim 15 further comprising; up-down
arpeggio control means, cooperating with said load means, for
loading said single 1 bit into one end position of said note scan
shift register and for conditioning said shift register and said
octave counter each to be incremented during an up arpeggio cycle,
and for loading said single 1 bit into the other end position of
said note scan shift register and for conditioning said shift
register and said octave counter each to be decremented during a
down arpeggio cycle.
17. Apparatus according to claim 16 wherein said up arpeggio
control means successively conditions said note scan shift register
and said octave counter alternately for up and down arpeggio,
together with start-stop switch means for initiating and
terminating the resultant alternate up and down arpeggio.
18. Apparatus according to claim 14 further comprising;
a set of keyboard contacts wired so that like notes in different
octaves are connected to a common buss associated with a respective
storage location in said note storage means, and
load means, operative at the start of arpeggio, for entering
note-indicating signals into locations of said storage means for
notes selected at any octave of said keyboard via the contacts and
busses associated with the selected notes.
19. Apparatus according to claim 14 for producing harp arpeggio,
comprising:
a note counter, operative during the first sequential scanning of
said storage locations, for counting the number of produced
tones,
harp count storage means for providing a "harp count" equal to said
counted number of produced tones plus a constant,
said note counter being operative during subsequent sequential
scanning of said storage locations to count the number of tones
produced since resetting of said counter, and
comparator means for comparing the counted number of tones since
resetting with said "harp count" and for decrementing said octave
counter and resetting said note counter each time an equal
comparison is obtained.
20. Apparatus for producing glissando automatically in an
electronic musical instrument, comprising;
note scanning means for repetitively, successively providing
signals indicative of all notes in a single octave of a musical
scale,
an octave counter, preset to a certain value and advanced by one
each time said note scanning means provides signals indicative of
all notes of an octave, said indicative signals and the contents of
said octave counter repsectively specifying the note and octave of
each tone produced by said musical instrument,
range selection means for selection of the starting and ending
notes of said glissando,
glissando range scanning means, actuated at the same time as said
note scanning means, for scanning the same musical range in unison
with said note scanning means and said octave counter, and
tone inhibit means for preventing tone production by said musical
instrument until said glissando range scanning means detects the
starting note selected by said range selection means, and
thereafter enabling such tone production until detection by said
range scanning means of said selected ending note.
21. Apparatus according to claim 20 wherein said note scanning
means comprises circuitry for selectively providing note-indicative
signals for either the chromatic of diatonic scale, and wherein
said range selection means comprises a set of contacts actuated by
a keyboard of said musical instrument.
22. Apparatus according to claim 20 wherein said glissando range
scanning means comprises;
a counting device having a range equal to said same musical
range,
scan clock means for providing high speed scan pulses to both said
counting device and said note scanning means to scan said musical
range at a high speed prior to detection of said starting note,
and
note duration timing means for advancing said scanning by said note
scanning means and said glissando range scanning means at a
relatively much slower rate during glissando production between
detection of said starting and ending notes.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the automatic production of
arpeggio and glissando effects in an electronic musical
instrument.
2. Description of the Prior Art
Arpeggio is the playing of consecutive notes of a chord in rapid
succession. Usually the chord is repeated through successive
octaves. In glissando, consecutive tones of either the chromatic or
diatonic scale are played in rapid sequence. Both effects are
difficult to play, demanding considerable skill and dexterity of
the musician. Automatic production of arpeggio and glissando adds
these otherwise difficult effects to the repertoire of even a
novice player. It is the principal object of the present invention
to implement arpeggio and glissando automatically in an electronic
musical instrument.
Certain features are desirable. These include ease of selection of
the arpeggio chord, i.e., the notes to be included in the arpeggio.
Another is flexability of the arpeggio mode. For example, the
arpeggio chord may be repeated for all octaves from lowest to
highest ("up-arpeggio") or from highest to lowest octave
("down-arpeggio"). Alternatively, the arpeggio may progress
successively up and down either once or continuously. In a "harp"
mode, the arpeggio chord is repeated through one octave and part of
the next; the octave then is backtracked and tone production
continued from the next note of the chord. Another object of the
present invention is to implement each of these alternative
arpeggio modes.
For automatic glissando production, a desirable feature is keyboard
selection of the beginning and ending notes. Another object of the
present invention is to implement such keyboard selection of the
glissando range. In a strum mode, the glissando or arpeggio is
produced repetitively.
Certain arpeggio systems for electronic organs are known.
Illustrative is the automatic arpeggio described in the U.S. pat.
No. 3,725,562 to Munch, Jr., et al. In that system, a series of
tone gates is scanned by a sequential readout comprising a
plurality of counter stages. Each such counter stage normally is
configured as a monostable multivibrator with a time constant on
the order of 30 microseconds. However, if a tone is to be supplied
by the associated tone gate, the counter stage is reconfigured to
act as a clock controlled bistable flip-flop.
To accomplish scanning, a pulse is rippled down the counter chain.
For those stages corresponding to gates where no tone is present,
the pulse is rapidly propagated by the one-shot counter
configuration. However, at those counter stages for which a tone is
to be generated, pulse propagation is delayed for a time interval
established by a clock which controls the switching duration of the
bistable flip-flop configured counter stage.
Another object of the present invention is to provide an arpeggio
system which is less complex and more flexible than those known in
the prior art.
SUMMARY OF THE INVENTION
These and other objectives are achieved by providing an arpeggio
system wherein note selection signals corresponding to the desired
arpeggio chord or glissando scale are entered in a single octave
note storage register. The note storage register is scanned
sequentially and repetitively at high speed under the control of a
note scan storage register. Scanning is suspended for tone
generation each time that a note-selection signal is detected. An
octave counter, incremented at the completion of each complete scan
of the note storage register, specifies the octave of the generated
tones.
Alternative arpeggio modes are implemented. These include up- or
down-arpeggio in which tone generation is terminated after a single
scan of the complete instrument range; a single up-down mode in
which the arpeggio is repeated once up and then once down through
all octaves; and a continuous up-down mode in which arpeggio
production is repeated in alternate directions. The "harp" mode is
implemented by comparing the number of tones generated by the
arpeggio circuit with a "harp count" equal to one greater than the
number of notes in the selected arpeggio chord. Each time a
comparison is obtained, the octave register is left shifted by one
position to continue the arpeggio generation from a position one
octave lower.
For glissando, the notes of the chromatic or diatonic scale are
entered into the note storage register. The musician selects the
beginning and ending notes of the glissando range by depressing
corresponding keys on the keyboard. These keys are scanned by a
glissando range shift register incremented in unison with the note
scan shift register and the octave counter. Tone generation is
enabled when the beginning note is detected by the glissando range
shift register, and is terminated when the ending note is detected.
In a strum mode, completion of the glissando range shift register
scan provides a pulse which restarts the glissando operation.
BRIEF DESCRIPTION OF THE DRAWINGS
A detailed description of the invention will be made with reference
to the accompanying drawings wherein like numerals designate
corresponding elements in the several FIGS.
FIG. 1 is an electrical schematic diagram of circuitry for
producing arpeggio automatically in a keyboard electronic musical
instrument.
FIG. 2 is a set of waveforms related to operation of the circuit of
FIG. 1.
FIG. 3 is an electrical block diagram of circuitry for controlling
the amplitude envelope of tones produced during an arpeggio
controlled by the circuitry of FIG. 1.
FIG. 4 is an electrical block diagram of a modification to the
circuit of FIG. 1 for producing an "up-down" arpeggio.
FIGS. 4A and 4B are electrical schematic diagrams of circuitry for
initiating and terminating continuous up-down arpeggio.
FIG. 5 is an electrical block diagram of system for producing
glissando automatically.
FIG. 6 is an electrical block diagram of a modification to the
circuit of FIG. 5 for operation in the "harp" mode.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following detailed description is of the best presently
contemplated modes of carrying out the invention. This description
is not to be taken in a limiting sense, but is made merely for the
purpose of illustrating the general principles of the invention
since the scope of the invention best is defined by the appended
claims.
Operational characteristics attributed to forms of the invention
first described also shall be attributed to forms later described,
unless such characteristics obviously are inapplicable or unless
specific exception is made.
The system 10 of FIG. 1 operates in conjunction with an electronic
musical instrument to produce arpeggio automatically. The notes to
be included in the arpeggio are selected on the instrument keyboard
switches 11 and stored in a note storage register 12 which is a
single octave in length. The note storage register 12 is scanned
repetitively at high speed by a note scan shift register 13 and its
associated circuitry, described below. An octave counter 14 is
incremented each time the note storage register 12 is scanned
completely.
Whenever a note-indicating signal is detected in the note storage
register 12, scanning is suspended to permit tone generation for a
time period established by a note duration monostable multivibrator
(one-shot) 15. The detected note-selection signal from the storage
register 12 is supplied via one of the lines 16 to the tone
generators of the associated musical instrument, and indicates
which note is to be produced. Simultaneously, a signal is supplied
from the octave counter 14 via one of the lines 17 to the same tone
generators. This signal specifies the octave of the produced note.
In this manner, the successive note- and octave-indicating signals
supplied to the associated musical instrument cause generation of
an arpeggio beginning at the lowest octave and continuing through
the highest octave of the instrument. The same selected notes are
repeated in order for each octave.
In the embodiment of FIG. 1, the notes included in the arpeggio
chord are selected by depressing the corresponding keys in any
octave. For example, if an arpeggio including the notes C and E is
desired, the C and E keys in any octave are depressed. This will
cause corresponding C- and E-note-indicating signals to be entered
into the note storage register 12 when a "start arpeggio" switch 19
is closed.
To this end, the note storage register 12 has twelve storage
locations 12-1 through 12-12 corresponding to the twelve notes of
the chromatic scale. The instrument keyboard switches include an
extra set of contacts 11 each receiving a voltage +V via a buss 20.
All switches 11 related to like notes are connected via a common
buss to the corresponding input of the note storage register 12.
Thus all of the switches C.sub.2, C.sub.3, C.sub.4. . .C.sub.7 are
connected via a line 21-1 to the storage location 12-1. Similarly,
each of the C.music-sharp. switches is connected via a line 21-2 to
the storage location 12-2.
The note storage register 12 advantageously comprises a
parallel-in, parallel-out-storage register wherein data is entered
upon application of a "load" signal. In the system 10, a "load"
signal 24 (FIG. 2) is supplied via a line 25 from a one-shot 26
when the start switch 19 is closed. Thus e.g., to load the notes C
and E into the note storage register 12, the C and E keys in any
octave are depressed (see waveshapes 27 and 28 in FIG. 2) and the
start button 19 is closed. The corresponding note-selection signals
then are stored in the locations 12-1 and 12-5 of the note storage
register 12.
The note scan shift register 13 also comprises a parallel
in-parallel out shift register having twelve storage locations 13-1
through 13-12 associated wth respective locations in the note
storage register 12. A single 1 bit is loaded into the first
location 13-1 upon occurrence of the "load" signal 24. This 1 bit
is successively shifted through the shift register 13 and functions
to enable readout of the corresponding location in the note storage
register 12. Thus when the location 13-1 contains the 1 bit, an AND
gate 30-1 is enabled to supply on a line 31-1 the contents of the
note storage location 12-1. Similar AND gates 30-2 through 30-12,
respectively associated with the note storage locations 12-2
through 12-12, are enabled when the single 1 bit in the shift
register 13 is situated in the corresponding location 13-2 through
13-12. Thus as the 1 bit is shifted through the note scan shift
register 13, any note-selection signals contained in the note
storage register 12 will appear on the corresponding AND gate
output lines 31-1 through 31-12. These lines enter an OR gate 32
which provides an output on a line 33 any time that a
note-indicating signal is accessed from the note storage register
12. This output, supplied via an enabled AND gate 34 to a line 35
constitutes a "play" signal 36 (FIG. 2) which directs the
associated musical instrument to generate the designated note.
The note scan shift register 13 is shifted at high speed by timing
pulses 37 (FIG. 2) from a scan clock 38. These timing pulses are
supplied via an AND gate 39 and a line 40 to the "shift" input of
the register 13. Whenever a note-selectional signal is accessed
from the storage register 12, the AND gate 39 is inhibited for the
duration of note production. To this end, the AND gate 39 receives
one enable input via a line 41 from an OR gate 42. The line 33 is
connected via an inverter 43 to the OR gate 42. When no
note-selection signal is accessed from the storage register 12, the
line 33 will be low, hence the output of the inverter 43 will be
high and an enable signal will be supplied via the OR gate 42 and
the line 41 to the AND gate 39. As a result, pulses from the scan
clock 38 cause shifting of the single 1 bit in the note scan shift
register 13. Eventually the 1 bit will reach a location
corresponding to that in which a note-selection signal is stored in
the note storage register 12. As a result, the signal on the line
33 will go high, the output of the inverter 43 will go low,
terminating the signal on the line 41 and disabling the AND gate
39. No more shift pulses reach the register 13, so that no scanning
is suspended.
The signal which appears on the line 33 at the beginning of note
production is supplied via an AND gate 45 to trigger the note
duration one-shot 15. The output 46 (FIG. 2) is supplied via an
inverter 47 to an "end of note" one-shot 48. This one-shot 48
provides a short duration pulse 49 (FIG. 2) on a line 50 at the end
of the duration of note production. Occurrence of this pulse 49
enables the AND gate 39 to provide at least one more shift pulse to
the shift register 13. That is, note scanning is restarted.
If no note-selection signal is present in the next scanned location
of the note storage register 12, the signal on the line 33 will go
low, enabling the supply of additional shift pulses to the note
scan shift register 13. On the other hand, if the next scanned
location of the note storage register 12 does contain a note
selection signal, the line 33 will stay high, and scanning again
will be inhibited. The duration during which this new note is
generated again will be established by the one-shot 15. To insure,
this, the end of note pulse 49 on the line 50 is supplied via an
inverter 51 to an enable input of the AND gate 45. As a result, the
input to the one-shot 15 will be interrupted briefly at the end of
the prior note. This insures that the one-shot 15 will function
properly to time the generation of two notes designated by
note-selection signals in adjacent storage locations of the note
storage register 12.
In the embodiment of FIG. 1, the arpeggio begins at the lowest
octave (typically octave 2) and continues through the highest
octave (e.g., octave 7). To accomplish this, the octave counter 14
contains six storage locations 14-1 through 14-6 each associated
with a respective octave 2 through 7. At the start of arpeggio
production, the "load" signal 24 on the line 25 causes a single 1
bit to be entered into the first shift register position 14-1 of
the octave counter 14. The corresponding output signal on the line
17-1 indicates that notes are to be produced in octave 2.
At the end of each complete scan of the note storage register 12,
the single 1 bit in the note scan shift register 13 is reentered
into the first location 13-1 via a line 53. The signal on the line
53 also is provided to the shift input of the octave counter 14,
which advantageously comprises a parallel-in, parallel-out shift
register. Occurrence of the pulse on the line 53 causes the single
1 bit in the octave counter 14 to be advanced to the next location.
The resultant signals on the lines 17 designate the octave of the
notes to be generated in unison with repetitive scanning of the
note storage register 12. Arpeggio production is terminated after
scanning in the highest octave of the musical instrument.
To this end, an "enable play" flip-flop 54 is set to the 1 state by
the "load" pulse 24 at the beginning of arpeggio production. The
resultant "enable play" signal 55 (FIG. 2) on a line 56 enables the
AND gates 34 and 39 during arpeggio production. When the highest
available note of the associated musical instrument has been
scanned, the flip-flop 54 is reset to the 0 state, terminating the
"enable play" signal 55 and disabling the AND gates 34 and 39. No
further scan clock 38 pulses are supplied to the shift register 13,
thereby terminating the scanning operation. Provision of the "play"
signals on the line 35 also is terminated.
In the system 10, the flip-flop 54 is reset after scanning of the
highest available note C.sub.7 (the note C in octave 7). This is
accomplished by providing the C.music-sharp. scanning signal on the
line 16-2 and the octave 7 signal on the line 17-6 to an AND gate
57. Accordingly, an output from the AND gate 57 occurs just
subsequent to scanning of the highest note C.sub.7. This output
supplied via a line 58 resets the "enable play" flip-flop 54 to
terminate he arpeggio.
Operation of the system 10 (FIG. 1) is illustrated by the waveforms
of FIG. 2, most of which have been described above. The lines 60
and 61 respectively designate the contents of the note scan shift
register 13 and the octave counter 14 during the arpeggio
operation. The curve 62 indicates the periods during which the AND
gate 39 is enabled to provide shift pulses to the note scan shift
register 13.
During an arpeggio, each individual note is produced for a
relatively short time duration. During this note duration it may be
desirable to shape the amplitude envelope so that the tone exhibits
pleasing attack and decay characteristics. Such amplitude envelope
control is provided by the circuitry 60 of FIG. 3 which functions
in conjunction with the arpeggio system 10 of FIG. 1.
Attack and decay is accomplished by providing successive amplitude
scale factors from a memory 61 via a line 62 to the associated
musical instrument. These scale factors are selected to provide the
desired attack and decay characteristics. In the musical
instrument, an appropriate circuit such as a multiplier scales the
amplitude of the generated note by the provided scale factor. As a
result, the generated tones exhibit the desired attack and decay
characteristics. For example, in a COMPUTOR ORGAN such as that
described in the inventor's corresponding patent application Ser.
No. 225,883 filed Feb. 14, 1972, and now U.S. Pat. No. 3,809,786,
the harmonic coefficients used to establish the amplitudes of the
generated tones are multiplied by the attack/decay scale factors
supplied from the circuit 60 (FIG. 3) to accomplish envelope
scaling.
The circuit 60 replaces the one-shot 15 and the inverter 47 of FIG.
1. Instead, the output of the AND gate 45 is connected via a line
63 to an AND gate 64 which gates scale factor timing pulses from an
attack/decay rate clock 65 to the shift input 66 of an attack/decay
shift register 67 used to access sequentially the scale factor
memory 61. An output line 68 from the final position 67-0 of the
shift register 67 is connected to the input of the end-of-note
one-shot 48 (FIG. 1). The shift pulses supplied via the line 40 to
the note scan shift register 13 also are provided to the "load"
input of the attack/decay shift register 67. The effect is to enter
a single 1 bit into the first position 67-1 of the shift register
67 at the time that each location of the note storage register 12
is scanned. Thus if that storage position contains a note selection
signal, the circuit 60 is conditioned to begin readout of the
attack/decay scale factors.
Appearance of a note selection signal on the line 33 produces a
concomitant signal on the line 63 which enables the AND gate 64.
Attack/decay rate pulses are supplied via the line 66, causing the
single 1 bit to shift from position to position in the attack/decay
shift register 67. The memory 61 stores the appropriate attack and
decay scale factors in successive storage locations 61-1 through
61-n having a one-to-one correspondence with locations 67-1 through
67-n in the shift register 67. The memory 61 is designed so that
the scale factor in the storage location corresponding to the
present location of the single 1 bit in the shift register 67 is
read out onto the line 62. With this arrangement, the successive
attack and decay scale factors will be supplied via the line 62 to
the associated musical instrument as the single 1 bit is shifted
through the shift register 67. The produced note will have a
resultant amplitude envelope defined by the scale factors which are
supplied at a rate established by the clock 65.
After all of the scale factors have been supplied to the associated
instrument, the 1 bit reaches the end position 67-o. Accordingly, a
signal is supplied via the line 68 to the end of note one-shot 48
(FIG. 1) thereby terminating note production. In this manner, the
duration of tone production is controlled by the attack/decay shift
register 67 in conjunction with the rate clock 65.
In the embodiment of FIG. 1, the produced arpeggio begins at the
lowest octave and ends at the highest octave. By using the optional
circuitry 70 of FIG. 4, an "up-down" arpeggio is obtained. The
notes first are produced going upward from the lowest to the
highest octave, followed by a reverse or downward arpeggio starting
from the highest octave and ending with notes of the lowest
octave.
To implement such up-down arpeggio, the note scan shift register 13
(FIG. 1) is replaced by a shift register 13' capable of either
right or left shifting. Similarly, the octave counter 14 is
implemented by a right/left shift register 14' (FIG. 4). The shift
register 13' and 14' each have a right/left control input. When a
low or 0 signal is supplied to this input, a right shift occurs
each time a shift pulse is received. If a high or binary 1 signal
is supplied to the control input, a left shift occurs.
Using the optional circuitry 70, operation during the up arpeggio
is identical to that described in FIG. 1. During this time, a 0 or
right shift signal is supplied via a line 71 to the right/left
control inputs of the shift registers 13' and 14'. This control
signal is supplied from an "up-down" flip-flop 72 which initially
is set to the 0 or "up" state by the load signal 24 present on the
line 25 at the start of the arpeggio.
Upon completion of the up-arpeggio, an output is obtained from the
AND gate 57. In the embodiment of FIG. 4, this output is not
supplied to the flip-flop 54 as shown in FIG. 1, but rather is
supplied to the set (S) input of the up-down flip-flop 72. As a
result, this flip-flop 72 is set to the 1 or "down" state upon
completion of the up-arpeggio. When so set, the flip-flop 72
provides a 1 signal on the line 71 which conditions the shift
register 13' and 14' for left shifting. In this manner, both the
notes and octaves are scanned from the highest to the lowest
positions during the down-arpeggio.
The octave counter 14' is shifted once for each complete scanning
of the note storage register 12. In the circuit 70, shift pulses
are supplied to the octave counter 14' via a line 73 from an OR
gate 74. During the up-arpeggio, the line 53 is connected to the
line 73 via the OR gate 74 and an AND gate 75 enabled by the 0
output from the flip-flop 72. Thus, the octave counter 14' is
incremented in exactly the same manner as that described in FIG.
1.
During the down-arpeggio, the single 1 bit in the note scan shift
register 13 is shifted to the left, starting from the location
13-12 and ending at the location 13-1. The signal then is
re-entered in the highest position 13-12 via a reset line 76. The
same signal on the line 76 is supplied to the shift input of the
octave counter 14' via the OR gate 74 and an AND gate 77 enabled by
the "1" signal on the line 71. In this manner, the octave counter
14' is shifted to the left (downward) each time a complete downward
scan of the note storage register 12 has been completed.
To terminate the up-down arpeggio, the octave counter 14' has an
extra storage location 14-0 at its low end. Thus, after complete
scanning of the lowest octave, the single 1 bit in the octave
counter 14' will be left shifted into this end position 14-0.
Accordintly, an output will be provided from an AND gate 78 enabled
by the 1 signal on the line 71. This output is supplied via the
line 58 to the reset (R) input of the "enable play" flip-flop 54
(FIG. 1). Occurrence of the signal on the line 58 resets this
flip-flop 54 to terminate arpeggio production.
The circuits of FIG. 4A and 4B permit implementation of continuous
up-down arpeggio. Unlike the circuit of FIG. 4, which terminates
after a single up and down scan, the circuit 80 of FIG. 4A permits
the arpeggio to continue so long as a switch 81 is closed. In the
circuit 82 of FIG. 4B, the arpeggio begins when a "start" switch 83
is depressed. The arpeggio continues alternately up and down until
terminated by depression of an "end" switch 84.
The circuit 80 (FIG. 4A) provides an input to the "start" one shot
26 (FIG. 1) in place of the switch 19. That is, the switch 19 is
not used, and the line 85 from an inverter 86 is connected to the
input of the one shot 26. When the switch 81 is open, the inverter
86 receives a high signal represented by the voltage +V supplied
via a resister 87. As a result, the line 85 is low. When the switch
81 is depressed, the input to the inverter 86 goes low, since it is
now connected to ground. Accordingly, a high output occurs on the
line 85 which triggers the one shot 26 to start the arpeggio.
To terminate the arpeggio, the output of a one shot 88 is supplied
via a line 58b to the reset (R) input of the "enable play"
flip-flop 54 in place of the output from the AND gate 78 (FIG. 4).
While the switch 81 is closed, the one shot 88 receives a low
input. As soon as the switch 81 is opened, a high input is applied
to the one shot 88, resulting in production of a pulse on the line
58b which resets the "enable play" flip-flop 54 to the 0 state,
thereby terminating the arpeggio. The output from the AND gate 78
(FIG. 4) advantageously is connected to the reset (R) input of the
"up-down" flip-flop 72 in place of the line 25. This insures that
if the switch 81 remains closed for several up-down cycles, the
flip-flop 72 will be reset at the end of each down arpeggio. This
switch 81 may be knee-controlled.
The circuit 82 (FIG. 4B) is connected similarly to that of FIG. 4A.
However, here the one shot 88 is triggered by a high pulse which
results when the input to an inverter 89, connected via a resistor
90 to the +V voltage source, is grounded by closure of the switch
84.
Glissando is produced by the circuit 93 of FIG. 5 which is a
modification of the system 10 of FIG. 1. Either chromatic or
diatonic glissando is selected by closing one of the respective
switches 94 or 95. The glissando range is established by depressing
two keys to close a corresponding pair of auxiliary switch contacts
11a. When the start switch 19' then is closed, the circuit 93
produces a glissando automatically, beginning at the lowest note
selected by the keyboard switches 11a and continuing to a higher
note corresponding to the other of the closed switches 11a. If
chromatic glissando is selected, every note in the selected
glissando range will be played in order. If diatonic glissando is
selected, only the notes of the diatonic scale are produced,
beginning and ending at the notes selected via the key contacts
11a.
For glissando, note-selection signals are supplied to the note
storage register 12 via circuitry including the switches 94 and 95.
For chromatic glossando, closure of the switch 94 applies inputs to
all of the note storage register positions 12-1 to 12-12 via a line
96 and the twelve OR gates 97-1 through 97-12 associated with the
respective storage register locations. For diatonic glissando,
closure of the switch 95 provides a note-selection signal to each
location of the note storage register 12 associated with a note (C,
D, E, F, G, A and B) of the diatonic scale. The arpeggio key
contact busses 21-1 through 21-12 also may be connected to the note
storage register 12 via the OR gates 97-1 through 97-12. However,
during glissando production the voltage would be removed from the
buss 20 (FIG. 1) so that the note storage register 12 is only
loaded with the appropriate chromatic or diatonic glissando note
selections signals.
Glissando range selection utilizes an extra set of keyboard
contacts 11a separate from the arpeggio contacts 11 (FIG. 1) but
operated by the same keyboard. The selected beginning and end keys
of the glissando range are held down (i.e., closed) during
glissando production. The position of these keys is detected by a
glissando range shift register 98 which scans the keyboard in
unison with glissando note production.
To this end, the glissando range shift register has a number of
storage locations 98-l through 98-m corresponding to the number of
keys on the instrument keyboard. For example, in an electronic
organ having a keyboard extending from C.sub.2 through C.sub.7, the
shift register 98 would have m=61 register positions. When the
start glissando switch 19' is closed, a single 1 bit is loaded into
the first position 98-l of the shift register 98. This 1 bit is
shifted through the register 98 by the same shift pulses on the
line 40 used to advance the note scan shift register 13. Thus the 1
bit in the shift register 98 always is situated in the register
position corresponding to the note currently available for
production; as specified by the contents of the note scan shift
register 13 and the octave counter 14.
In the glissando circuit 93, the AND gate 34 is enabled by a
"glissando enable" flip-flop 99 rather than by the "enable play"
flip-flop 54. When the start glissando switch 19' is closed, the
"glissando enable" flip-flop 99 is reset to the 0 state, thereby
disabling the AND gate 34. No "play" signal will be supplied to the
associated musical instrument until the "glissando enable"
flip-flop 99 is set to the 1 state upon detection of the selected
beginning note of the glissando range. Such detection is
facilitated by the glissando range shift register 98 in conjunction
with the switch contacts 11a and a set of AND gates 101-l through
101-m each associated with a respective one of the switch contacts
11a.
When the 1 bit in the glissando range shift register 98 first
reaches a location corresponding to a closed switch 11a, the
corresponding AND gate 101 is enabled, providing a signal via an OR
gate 102 to the set (S) input of the "glissando enable" flip-flop
99. The resultant 1 output from that flip-flop on the line 103
enables the AND gate 34 to provide the "play" signals to the
associated musical instrument. This starts generation of the
glissando tones. Successive tones in the chromatic or diatonic
scale then are generated in succession, with the duration of each
note being established by the one-shot 15.
Eventually the 1 bit in the glissando range shift register 98 will
reach a position corresponding to the next closed switch contact
11a, which defines the end of the glissando range. As a result,
another signal will be provided to the OR gate 102 via one of the
AND gates 101. This signal will reset the "glissando enable"
flip-flop 99 to terminate glissando production.
The resetting occurs in the following way. The output from the OR
gate 102 is anded with the 1 flip-flop output on the line 103 by an
AND gate 104. The output of this gate 104 is supplied via a line
105, and OR gate 106 and a line 107 to the reset (R) terminal of
the "glissando enable" flip-flop 99. In FIG. 5, the keyboard
switches D.sub.2 and F.sub.5 are closed. For this example, the
glissando range begins at the note D.sub.2 and ends at the note
F.sub.5. At the beginning of glissando operation, after the start
switch 19' has been closed but before the starting note of the
glissando range has been detected, the note scan shift register 13
and the glissando range shift register 98 are shifted at a rapid
rate. This is accomplished by providing the 0 output of the
"glissando enable" flip-flop 98 via a line 108 to the input of the
OR gate 42'. The resultant output on the line 41 enables the AND
gate 39 to provide shift pulses from the scan clock 38 to the line
40. The requisite high speed shifting is achieved.
The glissando circuit 93 of FIG. 5 readily may be modified to
provide a "strum" effect wherein the notes in the selected
glissando range are produced repetitively. In the modification, the
shift register 98 has an extra position 98-n. After completion of
scanning the entire keyboard, the single 1 bit in the register 98
will be shifted to this final position 98-n. The resultant signal
on a line 109 is provided as an alternative trigger to the start
one-shot 26. This causes generation of another "load" pulse 24,
initiating a new glissando cycle. By providing an optional delay
circuit 109a in the line 109, the new cycle will not start
immediately. Tone generation continues repetitively in this strum
mode unitl the keys establishing the glissando range are released.
Thereafter, tone generation will cease, since the "glissando
enable" flip-flop 99 remains in the reset or disable state.
Operation in the harp mode is facilitated using the circuit 110 of
FIG. 6 in conjunction with the circuit 10 of FIG. 1. In this mode,
instead of playing notes straight up and/or down the keyboard,
after one octave plus one note, the octave counter 14 backtracks
one octave. Thus e.g., if the selected arpeggio notes are C, E and
G, the sequence produced in the harp mode will be:
C.sub.2 E.sub.2 G.sub.2 C.sub.3 E.sub.2 G.sub.2 C.sub.3 E.sub.3
G.sub.2 C.sub.3 E.sub.3 G.sub.3 C.sub.3 . . .
Such harp mode operation is achieved by counting the number of
selected arpeggio notes and adding one to this number to obtain a
"harp count." The octave register 14 then is left shifted by one
position each time the number of generated tones equals the "harp
count." This operation is carried out by the circuit 110.
A counter 111 is incremented each time a tone is generated. This is
accomplished by supplying the output of the note duration one shot
15 via a line 112 to the "count" input of the counter 111.
At the beginning of arpeggio generation, the "load" pulse 24,
supplied via the line 25 and an OR-gate 113 is used to reset the
counter 111 to zero. The "load" pulse also sets a flip-flop 114 to
the 1 state. During tone generation in the lowest octave, the
counter 111 is incremented each time a note is produced. Thus when
the single 1 bit reaches the final position 13-12 of the note scan
shift register 13 (FIG. 1), the contents of the counter 111 equals
the number of selected apreggio notes. This number is stored in a
storage register 115. To do this, the scan reset pulse on the line
53 (FIG. 1) is supplied via an AND gate 116, enabled by the 1
output of the flip-flop 114, to the "load" terminal of the storage
register 115. This causes the contents of the counter 111 to be
loaded via a line 117 into the storage register 115. The signal on
the line 53 also resets the flip-flop 114 to 0. This disables the
AND gate 116 so that the contents of the storage register 115 will
remain unchanged throughout the remainder of the harp mode arpeggio
generation.
The value 1 is added to the contents of the storage register 115 by
an adder 118. The sum, corresponding to the "harp count," is
provided via a line 119 to a first input of a compare circuit 120.
The second input to the comparator 120 is the contents of the
counter 111 supplied via the line 117.
Each time that the circuit 10 (FIG. 1) has directed generation of a
number of notes equal to the "harp count," the contents of the
counter 111 will equal the number provided on the line 119. As a
result, the comparator 120 provides an output signal on a line 121
which causes the octave counter 14 to left shift by one position.
The signal on the line 121 also resets the counter 111. Note
generation continues with the next sequential note, but one octave
lower than the last generated. The resultant tone sequence is
exactly that given above for the harp mode.
Various alternative embodiments readily are apparent. For example,
the arpeggio circuit of FIG. 1 may be configured for down-arpeggio,
instead of the up-arpeggio shown, by loading the 1 bits at the high
end of the note scan shift register 13 and the octave counter 14.
Left shifting in each register 13 and 14 will produce the
down-arpeggio. The attack/decay amplitude envelope circuitry of
FIG. 3 alternatively may be used in conjunction with the glissando
circuit of FIG. 5. In the strum mode, notes other than those of
chromatic or diatonic scale may be entered in the note storage
register 12, so that any desired chord may be strummed.
Intending to claim all novel, useful and unobvious features shown
or described, the applicant:
* * * * *