Description:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to the electronic production of musical tones and, more specifically, to a device for producing one or more musical patterns of bass tones having a tonic note selected by an instrumentalist.
2. Description of the Prior Art
In the area of automatically controlled musical instruments it has been only relatively recently that devices have been provided which automatically yield musical patterns that may be selected at will by an operator or instrumentalist.
One category of such instruments has been the rhythm accompaniment devices adapted to produce various rhythms. Some rhythm accompaniment devices are provided with an arrangement by which the beat of the device will be altered to conform to the beat of an instrumentalist playing on an associated primary instrument such as an electronic organ.
Rhythm accompaniment devices have been quite successful in the market place and have provided an added dimension to the playing of music. By utilization of a rhythm accompaniment device in connection with the play of a basic instrument, an instrumentalist can play the melody and the device will provide a rhythm accompaniment so that the end effect will be that of a full band.
While rhythm accompaniment devices play an important part in the modern musical world, their use has been restricted to the production of rhythms by actuation of circuits that simulate percussion instrument sounds. Thus, the device plays on its own, essentially independent of what the instrumentalist is doing. Normally, the instrumentalist will condition his beat to coincide with that of the rhythm accompaniment device, but in some cases the beat of the rhythm accompaniment device can be modified to follow the beat of the instrumentalist. However, even when the device is adapted to follow the beat of the instrumentalist, the only change in the musical output of the device is the beat or speed of the music since there is no change in the basic sound of the music.
In the area of providing accompaniment utilizing notes or tones, there are other problems that prevent an easy solution. The primary problem, of course, is that when a musical note or tone is produced there is a much greater interaction with the music being played by the instrumentalist than when a rhythm accompaniment is being produced. In the latter case, it is necessary to match the beat of the instrumentalist and the rhythm accompaniment, whereas in the former it is necessary that the notes or tones played produce the proper musical effect when combined with the notes being played by the instrumentalist. As a result, it is necessary that the instrumentalist have control over the tonal nature of the accompaniment being produced.
Some prior art attempts have been made to provide tonal accompaniment patterns. One such prior art arrangement utilizes an approach in which an instrumentalist can produce basic accompaniment patterns by successively actuating a pedal for each of the notes of the pattern. Such an arrangement is, of course, difficult for the instrumentalist to play and has a limitation on the number of notes that can be played without the instrumentalist wearing himself out.
Other attempts have provided tonal accompaniment characteristics by utilizing arrangements such as a series of keys to be depressed in rapid succession by an instrumentalist to provide a run of notes based on a note being played by the instrumentalist. Again, though, such arrangement is difficult for an instrumentalist and detracts from his play of the basic instrument.
In co-pending application Ser. No. 36,263 filed May 11, 1970 in the names of William Wangard and David Fleeton, entitled DEVICE FOR AUTOMATICALLY PRODUCING TONE PATTERNS BASED ON A TONIC NOTE and assigned to same assignee, a device is disclosed which provides tonal accompaniment patterns automatically once the tonic note is selected by the instrumentalist. The specific device includes a switching network actuated by electronically produced pulse patterns and by pedal switches actuated by the instrumentalist. The switching network involves a plurality of pedal gate circuits with each circuit having a plurality of individual pedal gates equal to the number of semitones in a musical octave. The switching network also includes a plurality of audio gates actuated by pulses from the pedal gates to pass tone generator signals to an output audio circuit.
While the device operates in a very satisfactory manner, the switching network is quite complicated and expensive. In some instances, each pedal gage comprises 13 electronic switches and there are nine pedal gates involved. 117 electronic switches are required, necessitating the usage of well over 200 diodes. In addition, a plurality of audio gates are connected in the switching network. Therefore, improvements in the switching network are desirable to lower the complexity and cost of the device.
SUMMARY OF THE INVENTION
The present invention is directed to the production of tonal accompaniment arrangements by providing a wholly automatic pattern of notes by a device in which a pattern of electronically produced pulses serves to actuate a tone signal means. The tone signal means includes one or more frequency generators or other tone signal generating means and multiple voltage and circuit means as a multiple conditioning means to vary the frequencies to obtain time-separated tone signal output of the frequency generators.
Each of a plurality of pedals or other switch means operated by an instrumentalist is connected to the tone signal means to determine the tonic note and to provide time-separated tone signals capable of controlling the production of a musical tone pattern. The tone signal means feeds an audio means through an interrelating means to produce the desired tonal arrangement or pattern.
In a manner similar to co-pending Ser. No. 36,263, the driving portion of the system includes a pulse generating circuit and a pattern switching arrangement. Various types of pulse generating circuits could be utilized, of course, but in this case spatially separated driving pulses are obtained by making use of signals obtained from the logic circuitry of a rhythm accompaniment device utilized in association with the present invention. The signals from the rhythm accompaniment device are passed through a logic circuit which provides positive going pulses for the pattern switch.
In the present embodiment, five separate patterns may be chosen by use of the pattern switch. Of course, the number of patterns supplied could be increased if desired. Actuation of a particular pattern switch connects the terminals to which the driving pulses are applied to corresponding control points. Each of the control points is associated with the tone signal means which comprises tone signal generator means, and multiple conditioning means cause the generator means to produce the pattern of tone signals as an output.
In some instances the pulses actuate a plurality of tone signal generator means such as oscillators which are set by associated circuitry and voltages to generate different frequencies to produce the desired pattern of tone signals which operate the audio means for production of the tone pattern. In other instances, the pulses actuate multiple voltage means for a single tone signal generator to provide a pattern of different voltages in a pattern which determines the tone signals fed to the audio means. In this manner, the tone signal means as disclosed herein operates without a switching network having pedal gates, audio gates and complicated diode circuitry.
The voltages fed to the tone signal generator means are determined by the particular pedal selected by the instrumentalist. Each pedal is also associated with a tonic note to determine the initial note in the predetermined pattern of tones. However, it should be noted that the tonic note may not be actually included in the musical pattern, although it does determine the notes that are played.
With multiple tone signal generators, the voltages fed to each generator can be the same or different with respect to a particular pedal. If the voltages are the same, the circuitry in the conditioning means associated with the generator means will differ. If the voltages differ, the circuitry can be the same or different.
With the single tone generator means, the multiple conditioning means is a source of multiple voltages which are fed in a time-separated pattern to the tone generator to produce the pattern of tone signals.
The tone signals are then passed through interrelating means to the audio means. Normally, audio means include amplifying and tone producing means. While, audio means can include a plurality of separate amplifying means with switching means to determine the particular amplifier, the preferred embodiments of this invention often require only a single amplifying means and tone producing means.
The tonal arrangement described herein could be utilized with any type of tonal accompaniment, but in these embodiments it is primarily related to a string bass accompaniment.
Accordingly, it is a primary object of this invention to provide a device that will automatically produce a desired pattern of musical tones based on a tonic note selected by an instrumentalist.
Another object of the invention is to provide a device which produces the desired pattern of musical tones without complicated diode switching networks.
Another object of the invention is to provide a device which produces the desired pattern of musical tones with a tone signal means directly actuated by electronically produced pulses.
Another object of the invention is to provide a device which produces the desired pattern of musical tones from a single amplifying and tone producing means.
These and other objects, advantages, and features of the present invention will hereinafter appear and, for purposes of illustration, but not of limitation, exemplary embodiments of the subject invention are illustrated in the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-5 are schematic circuit diagrams of one preferred embodiment of the present invention.
FIGS. 6-8 are schematic circuit diagrams of a second preferred embodiment of the invention.
FIG. 9 is a block diagram of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1-5 it can be seen that the preferred embodiment incorporates a driving means including a generating means 11 (FIG. 1) and a pattern switching means 13 (FIG. 2). Generating means 11 actually has two functions: a logic analysis function and amplifying function.
The logic function is performed by diodes 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, and 45 which serve as blocking diodes for positive pulses. Transistors 47, 49, 51, 53, 55, 57, 59 and 61 are normally saturated and are cut off by a negative pulse entering for example on base 63 of transistor 47. This causes a positive signal to be transmitted through diode 65 and resistor 67 to emitter follower 69. Capacitor 71 and resistors 67 and 73 serve to increase the duration of the pulse. Diode 75 serves to isolate outputs of the various emitter followers when connected together.
As previously indicated, the signals applied to the logic could be obtained from any convenient source, however in this particular embodiment they are derived from a rhythm accompaniment device 12 (illustrated as a box in FIG. 1) utilized in connection with the subject invention. The particular circuit in FIG. 1 utilizes negative logic signals produced from the rhythm accompaniment device 12. These signals are inverted by generating means 11 whose outputs are positive.
In a similar manner signals are produced in the circuits associated with emitter followers 77, 79, 81, 83, 85, 87 and 89.
The circuits associated with transistors 91 and 93 provide a means for controlling the sustain time of the tone signal produced by the tone generating means. The pulses produced by emitter followers 69, 77. 79. 81, 83, 85, 87 and 89 are connected through switching means as explained below to keying circuits which include sustain capacitors. For illustration purposes, emitter follower 69 is connected to keying input 109 in FIG. 3. The pulse produced by emitter follower 69 charges sustain capacitor 160. This is followed by the firing of emitter follower 77. When transistor 77 fires, current is drawn through resistor 97 and causes capacitor 99 to couple a negative pulse to transistor 91 which is normally held in saturation by resistor 95. When transistor 91 turns off, transistor 93 saturates momentarily which provides a discharge path for sustain capacitor 160 through resistor 155 and diode 163. This action prevents two tones from sounding simultaneously at fast tempos which, because of the low frequencies involved, would produce a very undesirable "burbling" effect. This circuit also allows the sustain length to be very long so that at slow tempos, a very sustained, "natural" sound is heard.
The outputs from the eight pulse generators are fed to terminals 101, 102, 103, 104, 105, 106, 107 and 108 in FIG. 2. Pulses appearing on terminals 101-108 are then passed to the pattern switching means 13. Pattern switching means 13 has five separate patterns, each of which includes eight normally open switches 100. Eight switches are utilized in each of the pattern switching arrangements in this embodiment to correspond to the eight pulse outputs of the driving circuit, which correspond to the eight quarter notes of two measures of 4/4 time utilized in this preferred embodiment. The invention is not, of course, limited to the use of this particular meter nor to only two measures. The five patterns that may be selected have been designated U, V, W, X and Y.
Selection of a particular pattern causes the associated switches 100 to connect terminals 101-108 to a series of control points designated by numerals 0-8. A control point designated by 0 is merely an open circuit connection. Each of the control points 1-8 is connected to a corresponding one of the keying inputs 1-8 illustrated in FIG. 3. Various keying inputs 1-8 are identified by numerals 109-117.
FIG. 3 illustrates a tone signal means adapted to provide time-separated tone signals capable of controlling the production of a musical tone pattern in which each tone is different from but related to each of the other tones in the pattern. The tone signal means comprises a tone signal generator means as illustrated by unijunction transistors 119-127 and means for conditioning the generator means as illustrated by voltage means 118 and circuitry associated with each of unijunctions 119-127.
For illustration purposes a circuit associated with unijunction 119 will be described. The voltage from source 118 is applied through timing resistors 129 and 131 and timing capacitor 133 to the anode 132 of unijunction 119. A reference voltage 134 from source 224 (FIG. 4) is applied to the gate 137 of unijunction 119 through programming resistors 136 and 136. As known, the relation between the voltage on anode 132 and gate 137 determines the firing point of unijunction 119. The values of timing resistors 129, 131 and timing capacitor 133 determine the time required for the voltage on the anode 132 to reach the firing point and thus determine the frequency of oscillation. Flip-flop 145 serves to isolate and stabilize the frequency of the signal generated by unijunction 119. Flip-flop 145 flips each time unijunction 119 fires, thus creating a square wave output having a frequency one-half the frequency of firing of unijunction 119.
The signal from flip-flop 145 is gated on by diodes 147 and 149 only when a positive pulse appears at terminal 109. Resistor 151 serves to limit leakage of high frequency components of the signal and capacitor 160 serves to sustain the signal. Resistors 157 and 159 are keying resistors. Resistor 168 is a loading resistor to prevent cross keying. As noted, resistor 155 and diode 163 serve to provide a discharge path for capacitor 160 through transistor 93 when a second circuit is keyed. The signal is fed to a voicing network represented by capacitor 165, coil 167 and resistor 169. The output of this circuit is fed to an audio means illustrated in FIG. 5 through line 510.
In FIG. 4 instrumentalist operated selection means 239 is illustrated which operates to condition the voltage means 118 illustrated in FIG. 3. The instrumentalist operated selection means 239 is comprised of resistors 184-197, switching circuits 227-237 and emitter follower transistor 223. For illustration when pedal switch 171 is closed, a positive voltage is applied to the base 221 of transistor 218. This cause transistor 218 to saturate and effectively grounds the junction of resistors 185 and 186 establishing a potential on the base of transistor 223 which in turn establishes a potential on the emitter of transistor 223 which is effectively the voltage on the base of transistor 223 minus the base to emitter voltage drop. Emitter of transistor 223 leads to voltage means 118. Diode 222 serves to compensate for the base-emitter drop in transistor 223. Capacitor 199 in the base circuitry of transistor 218 serves to hold transistor 218 into saturation for a short time after the pedal key switch 171 is opened. It should also be noted that as long as transistor 218 is saturated the similar switching circuitry associated with blocks 227-237 is inoperative.
Detection of the "key on" condition is accomplished by transistors 205, 206 and 207 and associated circuitry. This operates as follows: when pedal key switch 171 is closed, capacitor 199 charges from a source connected to point 500 through resistors 700 and 701 thus saturating transistor 205. Placing transistor 205 in a conducting state causes a positive voltage to appear on the base 211 of transistor 206 causing transistor 206 to conduct to supply a positive keying supply voltage from emitter 213 to the base of transistor 207 which causes transistor 207 to conduct. Since transistor 207 offers a conduction path from the supply voltage on point 500 through diode 201 and resistor 203 to ground, sufficient current is continually drawn through resistors 700 and 701 to maintain transistor 205 to maintain it in conduction after capacitor 199 reaches full charge. Therefore, transistor 207 is held in a conducting state as long as switch 171 (or any other applicable pedal switch 172-183) is held closed. An alternative selection means useful in this embodiment is a "ladder" switch arrangement which would selectively tap the voltage from a voltage dividing network.
The application of the voltage from voltage means 118 and the voltage 134 from source 224 (a conventional voltage regulator not described in detail, the supply voltage of approximately 20 volts is applied at point 500 and the regulated output voltages are indicated by the numerals 134, 334, 434, and 534) to the transistors 119-127 shown in FIG. 3 provide a reference voltage to the various transistors 119-127 which may be adjusted with the associated circuits (as illustrated by resistors 129 and 131 and capacitor 133) that causes each of the unijunction transistor circuits to oscillate at a predetermined frequency different from that of each of the other circuits in order to provide a plurality of frequencies corresponding to tone signals which are selectively keyed by the inputs from the pattern switching means 13 to provide time-separated tone signals through line 510 to the audio means illustrated in FIG. 5. FIG. 5 represents a standard preamplifier which amplifies and feeds the signal through line 512 to additional amplifying means and speaker means (not shown).
The pre-amplifier illustrated in FIG. 5 is essentially a conventional pre-amplifier. Bias for the pre-amplifier is obtained from terminal 241 and conveyed to the collectors of transistors 242 and 243. The collector 249 of transistor 242 is biased through resistor 244, while the base 245 is biased through resistors 246 and 247.
The input signal is connected to the base of transistor 242 through a capacitor 248, and the output on the collector 249 of transistor 245 is fed to terminal 241 through capacitor 250 for high frequency roll off and through capacitor 250 to base 251 of transistor 243 which is connected to ground through a resistor 252.
The emitter of transistor 242 and the emitter of transistor 243, which is connected in an emitter follower configuration, are connected to ground through resistors 253 and 254 respectively. The output obtained from the emitter of transistor 243 is conveyed to the audio circuitry 800 through a capacitor 255 Resistors 252 and resistor 256 serves to bias base 251 of transistor 243.
FIGS. 6-8 represent a second preferred embodiment which incorporates a driving means similar to that described in FIG. 1, a multiple conditioning means, a single tone generating means, instrumentalist selection means, audio means and an interrelating means to produce the desired time-separated tones. The instrumentalist operated selection means 327 illustrated in FIG. 6 is essentially identical to the selection means 239 described in FIG. 4. The output 347 of the pedal key switch 327 is fed to a voltage multiplex switch means 329, which is comprised of voltage dividing resistors 356-364 and field effect transistor switches 365, 371, 372, 373, 374, 375, 376, 377 and 378. The voltage multiplex means 329 serves to increase the total number of different available voltages. The inputs to voltage multiplex switch means 329 are positive pulses whose sequence is determined by pattern switch 401 as described below.
For illustration purposes, the circuitry for transistor 365 will be described. Normally, a negative bias voltage of about -5 volts is applied through resistor 380 and diode 368 to the gate terminal 366 of transistor 365. This bias prevents transistor 365 from conducting. When a positive voltage pulse is applied to terminal 367 from switch 401, the net voltage at the junction of resistors 379 and 380 is positive. This causes diode 368 to be reverse biased and cease conduction. The potential pedal output bus 347 is then applied through resistor 381 to gate 366 of transistor 365 which turns the transistor on and applies the potential appearing at terminal 347 to terminal 370. It can be seen that when transistor 371 turns on the voltage output on terminal 370 is reduced from that applied through transistor 365 because of resistor 356.
The voltage on terminal 370 is connected to the voltage controlled oscillator 382 through a high impedance isolating circuit illustrated by transistor 479, resistor 481 and capacitor 480. The output of the high impedance isolating circuit is passed to the voltage controlled oscillator 382 illustrated by resistors 383 and 384, capacitor 385, unijunction transistor 386, programming resistor 387 and 388 and resistor 389. The operation of the voltage controlled oscillator 382 is similar to that illustrated in FIG. 3 and described in connection with unijunction 119. Since the voltage appearing on resistor 383 controls the frequency of the oscillator 382, the particular voltages fed by voltage multiplexing switch 329 will determine the operating frequency of the oscillator. Flip-flop 390 serves to isolate and stabilize oscillator 382. Diodes 391 and 392 are keying diodes which serve to block the positive going excursions of flip-flop 390. Resistor 393 serves to shunt high frequency leakage caused by the shunt capacitance of diodes 290 and 391.
Keying voltage is inserted on terminal 399 to charge capacitor 412 and turn on diodes 391 and 392 through resistor 411. The keying voltage is modulated by the output of flip-flop 390. The tone signal is passed through resistor 394, capacitor 395 and inductor 396 to preamp means 397. Capacitor 398 serves as a filter capacitor. The output from preamp 397 is passed to an amplifying and sound producing means.
FIG. 7 illustrates a pulse generator 400 and keying circuit 402 while FIG. 8 schematically illustrates a pattern selecting switch 401. Pulse generator 400 is comprised of eight three-input AND gates. The inputs 420 to these gates are fed from the counter of rhythm accompaniment device 12. AND circuit 403 serves to illustrate the operation. The output from AND circuit 403 is positive only when all three of its inputs are positive. When this occurs the positive output is fed to switch 401 through contacts 501-508. Switch 401 is identical with the switching means illustrated in FIG. 2 except that the connections given by 0 are connected to a common keying inhibit bus 404 (FIG. 7). The positive output from AND circuit 403 is connected to the appropriate input of the voltage multiplexing switch 329 through selector switch 401. This allows the voltage multiplexing switch to apply the appropriate voltage to the voltage controlled oscillator 382 corresponding to a particular frequency of oscillation called for by the interaction of the instrumentalist operated selection means 327, pattern switch 401 and the particular state of the rhythm accompaniment counter inputs 420.
The keying circuit 402 is illustrated by resistor 416, capacitor 417, transistors 405, 406, 407 and 408 and diode 410. When any of the AND gates change state current is drawn through resistor 416 and a negative pulse is coupled to transistor 405. The chain of transistors 405-408 act to produce a positive pulse on emitter terminal 413 which is applied to diode 410 and is connected to keying input 399 in FIG. 6. The purpose of this circuit is to gate the output of flip-flop 390 to the pre-amplifier circuitry 397 each time an AND gate switches state. The operation of transistor 414 is to inhibit the keying operation of transistor 408 when the pattern from switch 401 does not produce an output (the pattern selected by switch 401 has a musical rest).
FIG. 9 is a block diagram of the present invention. Driving means 850 includes generating means 11 and pattern switching means 13 previously described. Selection means 852 includes the circuitry associated with switches 171-183 previously described. Reference signal means 854 includes the circuitry associated with transistor 223 which provides a reference voltage at 118. The tone generating means 856 includes the circuitry associated with unijunction transistors 119-127 previously described. Audio means 860 includes the circuitry associated with transistors 242 and 243 and audio circuitry 800 previously described.
Alternatively, tone generating means 856 includes multiplex switch means 329 and voltage controlled oscillator 382 as previously described.
From the above description it is seen that I have provided a device for producing musical tone patterns based on an instrumentalist selected tonic note. The device operates with a tone signal means adapted to provide time-separated tone signals capable of controlling the production of the musical tone pattern in which each tone is different from but related to each of the other tones in the pattern. The tone signal means utilizes tone signal generator means and multiple conditioning means electrically connected to the generator means to provide for the production of the time-separated tone signals.
The device also operates with instrumentalist operated selection means adapted upon operation to actuate the multiple conditioning means, audio means to produce the musical tones in the desired pattern, interrelating means adapted to cause the tone signals to control production of the musical tone pattern by the audio means, and driving means for actuating the tone signal means at predetermined times to provide the desired pattern of tone signals.
It should be understood that the embodiments described are merely exemplary of the preferred practice of the present invention and that various changes, modifications, and variations may be made in the details of construction, arrangement, and operation of the elements disclosed herein, without departing from the spirit and scope of the present invention.