Abstract: An electronic percussion instrument with a single cymbal and a displacement detection apparatus that detects the displacement of an electronic cymbal. The electronic percussion instrument is designed to allows users to simulate the performance feel of an acoustic cymbal with two cymbals. The single cymbal of the instrument moves vertically in conformance with the depression of a pedal to simulate the “open” and “closed” positions of an acoustic cymbal. The displacement detection apparatus electronically detects the vertical displacement of the cymbal in the electronic percussion instrument through measuring resistance change of the detector in conformance with the movements of the cymbal.

Abstract: A Cadence-Providing Drum Practice Pad Assembly and Method is disclosed. The preferred assembly combines a practice pad and a cadence generating device in the same body. In other embodiments, the device provides visual prompting to the user on the striking pad. Furthermore, the device of the present invention includes a local repository of cadence programs, as well as the ability to retrieve and play cadence programs stored in remote cadence repositories, such as on a computer network or a portable storage media. In one embodiment the device includes a mounting aperture that is offset from the center of the striking pad so that the pad will have a more realistic feel when mounted to a cymbal stand. Finally, the device may be provided in the form of a conga practice pad.

Abstract: A Cadence-Providing Drum Practice Pad Assembly and Method is disclosed. The preferred assembly combines a practice pad and a cadence generating device in the same body. In other embodiments, the device provides visual prompting to the user on the striking pad. Furthermore, the device of the present invention includes a local repository of cadence programs, as well as the ability to retrieve and play cadence programs stored in remote cadence repositories, such as on a computer network or a portable storage media. Still further, the device includes the option of connecting remote striking pads that can be attached to a conventional drum set to provide visual and/or audible cadence prompting at the drums themselves. Furthermore, the device is attachable to a conventional cymbal or drum stand. The device may also have the ability to play musical accompaniment for the user's enjoyment.

Abstract: A pressure-sensitive switch comprises a base member having a mounting surface formed of electrically-insulating material; two electrodes mounted on the base member and each having an electrically-conductive contact surface, and a flexible diaphragm having its periphery secured in a fluid-tight manner to the mounting surface with its electrically-conductive central portion overlying the contact surfaces of the electrodes. The diaphragm, which is formed with plural corrugations, is exposed to the external pressure. When the switch is exposed to atmospheric pressure, the central portion of the diaphragm does not touch the contact surfaces of said electrodes, but when the switch is exposed to a super-atmospheric pressure, this central portion is forced into contact with both contact surfaces, thus electrically connecting the two electrodes. This pressure-sensitive switch is especially useful for use with hydrophones, as in seismic streamer cables.

Abstract: A device to produce sub-harmonic tone signals in response to a tone signal from a transducer having preferably maximum sensitivity in the plane of bowing of a bowed musical instrument by passing selected cycles of the transducer signal through signal gates which are controlled jointly by sub-harmonic control signals at sub-multiples of the fundamental frequency of the transducer signal and by a signal indicative of the detection of a fundamental frequency. Each sub-harmonic tone signal thus produced has a tone color which approximates that of the corresponding bowed musical instrument of the same frequency range and which is independent of the direction of bowing.

Abstract: For electronically reproducing the total sound produced by a musical instrument, the musical instrument comprises a plurality of components each of which produces one aspect of the total sound, an electronic acoustic reproduction system comprises vibration transducer means mounted on the instrument for receiving the one aspect of the total sound from one of the components and transforming the one aspect to an electrical signal, and electronic filter means for processing the electrical signal to produce a total electrical signal representative of the total sound of the musical instrument.

Abstract: An electronic stringed instrument includes a mode selecting section for selectively setting a normal play mode and at least one other selection mode. When picking of a string under a pitch designation operation status is performed after the normal play mode is selected by the mode selecting section, generation of a musical tone with the designated pitch can be started. When picking of a string also under the pitch designation operation status is performed after another selection mode is selected by the mode selecting section, a desired musical tone parameter such as a timbre corresponding to the designated pitch or a rhythm pattern can be easily set. The content of the set musical tone parameter can be confirmed by a sound.

Abstract: A plurality of pad operating means for manual operation are provided on a keyboard panel of an electronic keyboard musical instrument. When an operator operates the pad operating means using the keyboard during melody play, an operation signal is supplied to a CPU, and a rhythm sound corresponding to the operated pad is generated under control of the CPU.

Abstract: A keyboard operated musical instrument is disclosed in which musical tones are created by computing waveshapes from a set of harmonic coefficients. Tones with time variant spectra are obtained by scaling each harmonic coefficient in response to a stored set of scaling numbers. An efficient scaling implementation is described which changes the harmonic coefficients by increments of a predetermined ratio. The tone generation system provides a significant reduction in the number of stored numbers in comparison with a simple stored waveform tone generator.

Abstract: An electronic musical instrument of the stringed type wherein bending of a string results in a change in a parameter of the sound produced. At the bridge of the instrument, each string is connected with a leaf spring which is moved towards the nut end of the instrument when the string is bent. Each leaf spring is connected with a Hall effect device, and the spacing between it and a permanent magnet is changed when the spring moves, thus causing a variation in the output of the Hall effect device, which variation alters a parameter of the audio output produced by a tone generator means.

Abstract: A plurality of envelope generating circuits provide output envelope waveforms which are controlled according to the output from a plurality of timbre switches. The envelope waveform of at least one of the envelope generating circuits is modified according to a touch data output of a touch data detecting circuit for detecting a way of operation of a performance key.

Abstract: An electronic musical instrument is provided with a temporal variation circuit of SCF parameters for temporally varying the filter characteristic of a switched capacitor filter circuit, a control circuit for digitally controlling the temporal variation circuit and a touch response circuit for detecting, by scanning, touch response data in performance, whereby temporal variations of a musical waveform signal are digitally controlled.

Abstract: A variable power amplifier having a constant current differential amplifier driving a cascaded driving amplifier, a variable power amplifier including a vacuum tube for selectively amplifying output signals wherein the drive of the variable power amplifier is determined by the plate shunt resistive loading of the vacuum tube, a push-pull amplifier including an output transformer operatively coupled to the variable power amplifier and to an amplifier output terminal to amplify and apply to the amplifier output terminal a selectively amplified output signal, and a variable damping circuit including a sensing element for sensing the loading on the output tranformer and a circuit for defining a feedback loop for producing a feedback signal having magnitude and polarity which are determined by the sensing element and wherein the variable damping circuit includes a circuit for applying the feedback signal as an input to the constant current differential amplifier to control the current level thereof as a function o

Abstract: A biasing and control circuit for varying the output power delivered by the push-pull output stage of a power amplifier is disclosed. The biasing and control circuit incorporates both fixed and cathode biasing to allow output power to be varied without introducing distortion. A negative fixed biasing voltage is applied to the control grids of the vacuum tubes comprising the push-pull output stage, while the cathodes of such tubes are varied between ground and selected voltage levels above ground. To vary the voltage levels, the cathodes of the tubes are joined together by a common connection and coupled to ground through a variable impedance which when varied changes the conductivity of the output tubes, and thereby, the output power delivered by the amplier.

Abstract: Musical tone color setting apparatus is arranged so that when a program/preset switch, a feet switch envelope switch and modulation switch are actuated together with a selected key of a ten-key input unit, program tone color data obtained by combining data selected from three groups of tone color data is stored in a tone color data memory. A tone color data corresponding to the program tone color data stored in the memory is later read out from a ROM, and a music sound having a tone color corresponding to the tone color data is generated from a loudspeaker in response to operation of a keyboard.

Abstract: An amplifier circuit for automatically altering in a controlled way the reproduced tones of an electronic piano comprises a main signal path for the fundamental tones and an overtone path including a plurality of tone altering electronic networks and field effect transistor amplifiers combining the networks. The circuit includes separate controls for manual adjustment of normal level gain, bass boost, overtone, output volume and gate control threshold. A mixer recombines the main path and the overtone path. A gate circuit may be provided to disable the overtone path when no signal is present in the main path over a predetermined minimum threshold. The entire device is constructed for mounting over the keyboard of the piano, with a panel for the controls which renders them readily accessible for regulation by the musician to obtain the desired improvement and alteration of the tones put out by the piano.

Abstract: In a musical instrument having one or more tone generators in which a plurality of data words corresponding to the amplitudes of a corresponding number of evenly spaced points defining the waveform of one cycle of a musical signal are transferred sequentially from a note register to a digital-to-analog converter in repetitive cycles at a rate proportional to the pitch of the tone being generated, apparatus is provided for producing tones having independent time-varying harmonic components. A recursive algorithm is implemented which approximates prespecified harmonic-time curves by piecewise segments of exponential functions. Only a small number of stored curve parameters are required to generate the harmonic-time scale factor for a set of harmonic coefficients.

Abstract: In an electronic musical instrument, a plurality of component elements of a musical tone are designated by a respective plurality of manual setting elements and preset in a preset memory device. A person operating the device can select a musical tone to be produced based on the component element preset in the preset memory device or the component elements formed by the manual setting elements or any combination of such preset and manually set component elements. A visual display is used to display the amount of operation of the manual setting elements.

Abstract: The disclosure describes an improved electronic musical synthesizer capable of storing, recalling, editing and restoring signals representing different timbres of sound. During the editing process, indicating circuitry enables a performer to determine whether the control knobs of the synthesizer have been adjusted to the same settings which resulted in the signals originally stored.

Abstract: The self-adjusting limit switch assembly of this invention has two switches mounted on a slide for sliding movement on a bracket. A transverse slot in the slide has two facing surfaces. The switches are mounted on each side of the slot with their operating members extending slightly past the slot. The actuator is positioned to extend into the slot. When the brakes are first moved to the brake released position the actuator engages not only the operating member of the switch on that side, but also a wall of the slot and moves the slide to a brake released position thereby correctly adjusting the position of the switches. When the brakes require adjustment due to wear, the actuator engages the operating member of the second switch, as before, causing an indicator to function.

Abstract: A tone source apparatus for an electronic musical instrument includes a sequentially addressable memory storing a plurality of waveform segment defining instructions, each instruction including a component representative of the amplitude variation, the time duration and the direction of change of the associated waveform segment. Output means comprising an adder-subtractor circuit and a latch is operated for accumulatively processing the stored amplitude variation representative components for producing a stepped output signal whose direction of slope is determined by the stored direction component. Control means interposed between the memory and the output means is selectively operable for modifying the stored amplitude variation components coupled to the output means for imparting a sinusoidal inflection to the stepped output signal.

Abstract: A transistor amplifier of the invention comprises a low power solid state simulator for a push-pull transformer-coupled vacuum tube power amplifier. The simulator develops overtones and distortion characteristics associated with a vacuum tube power amplifier, thereby producing a vacuum tube sound from the transistor amplifier.

Abstract: In an electronic musical instrument of the type comprising a musical tone signal generator responsive to depression and release of a key of a keyboard for generating a musical tone signal, and a selector including a plurality of tone color selection switches for selectively imparting a tone color to the musical tone signal, there are provided a detection circuit to detect variation in states of the tone color selection switches for producing a detection signal, a tone generation inhibit signal generating means responsive to the detection signal for generating a tone generation inhibit signal having a predetermined duration, and a circuit responsive to the tone generation inhibit signal for preventing generation of a musical tone.

Abstract: An electronic musical instrument generates musical tone signals by digitally executing the calculations of equations representing frequency modulation. The instrument comprises a keyboard information generating circuit for generating key information concerning depressed key numbers and key touch information concerning key operation, a plurality of system parameter generating circuits for providing parameter information in response to the outputs of a tone color selecting switch section, a plurality of system musical tone signal forming sections each for producing musical tone signals through the digital calculation of the FM equation in accordance with the abovementioned informations, and a musical tone generating section for producing musical tones by combining the musical tone signals provided by the musical tone signal forming sections, the musical tone signal forming sections calculating the FM equation by using different parameters provided by the parameter generating circuits.

Abstract: A pitch extractor for an electronic musical instrument generates a digital count indicative of the period of the signal whose frequency is to be extracted and processes this count to provide an analog control voltage corresponding to this frequency; the control voltage is usable to control an electronic music synthesizer. The rate at which the pitch is extracted is enhanced by initially setting the system for the expected pitch of the musical source and thereafter adjusting it to the actual pitch of the source in a closed-loop manner as extraction proceeds.

Abstract: In an electronic musical instrument, such as an electronic organ, certain organ voices are synthesized by applying a tone signal to a voltage controlled low-pass sharp cutoff filter, the pass characteristic of which has a relatively sharp knee and a rapid rate of rolloff, thereby to sharply attenuate the harmonics contained in the tone signal which have frequencies above the cutoff frequency. The filter works on the principle that by switching one or more frequency-determining resistors in and out of the filter network at a rapid rate and varying the time on versus the time off, the effective value of the resistance varies to thereby alter the cutoff frequency and the character of the resulting sound signal. In accordance with the present invention, precise control over the switching duty cycle is achieved by establishing a reference voltage to which is added a voltage increment according to a binary weighting determined by selection of a particular organ voice.

Abstract: An electronic sound system especially effective with bell sounds synthesizes the approximate sound of each bell in a set of 49 switch operated bell sounds. The synthesizing is accomplished by utilizig an envelope generator for each partial of a group of 7 partials for each of the 49 sounds, in association with a single 73 note wave generator. The envelope generators for low partials of each group of 7 are slow attack, slow decay relatively long envelopes. The envelope generators for the high partials of the same group of 7 are fast attack, fast decay relatively short envelopes, and envelopes for certain intermediate partials are fast attack with combined short and long decay envelopes of intermediate length. There is a single wave generator for each of 73 tones, the wave generators having circuits interconnecting them with partials of common frequency of the various groups of 7 partials for the respective keys.

Abstract: An electronic musical instrument, which enables a player easily to select by operating a switch any of a plural number of tone colors from a large number of tone colors originally preset in the musical instrument in a form of tone color data stored in a memory unit, to thereby more easily carry out a performance within a broadened range of performance techniques.

Abstract: The disclosure describes improved apparatus for sampling a digitally-stored waveshape only at a rate 2.sup.N times the fundamental frequency of a note synthesized, where N is an integer. The apparatus includes a digital memory for storing a digital representation of the waveshape. A top octave synthesizer produces clock pulses at a rate 2.sup.N times the fundamental frequency of a desired note. An octave oscillator generates addresses for the digital memory in response to at least some of the clock pulses depending on the octave in which the desired note is located. A digital-to-analog converter converts the output from the digital memory into an analog signal suitable for sound production.

Abstract: A method for producing a tone waveform having a desired spectral construction by modulating an input address signal of a selected frequency for a waveform memory. For the modulation of the input address signal, the output of the waveform memory is multiplied by a parameter .beta. of a suitable value and the multiplication product is added to the input address signal. If the input address varies in the manner of, for example, a saw-tooth wave, a desired tone waveform can be produced within a range between a saw-tooth wave and a sinusoidal wave by selecting a suitable value of the parameter .beta.. More specifically, a saw-tooth wave is produced as a tone wave form if a sufficiently large value of .beta. is selected. As .beta. is gradually decreased, the amplitude is decreased from a higher order and the amplitude also disappears from a higher order until the tone waveform becomes a sinusoidal wave when .beta. is zero.

Abstract: An electronic music synthesizer capable of simulating a wide variety of musical effects, wherein the settings which create the various effects are hard wired on a plurality of selectable circuit boards so that programming of the instrument can be accomplished by the player with minimum effort. The synthesizer encodes a plurality of keys on the keyboard and selects a tone from the tone generator corresponding to the depressed key. This tone is fed through a chain of dividers to create the needed footages, which are then fed to voicing cards that create the different tone sources for the synthesizer. These tone sources are fed into a state variable active filter which modifies the timbre of the tone sources in order to achieve the desired frequency-related effects.

Abstract: An electronic musical instrument for producing a vocal sound signal comprising a musical tone signal generator connected to a passing circuit for passing a musical tone signal under the selection of a key. A formant filter is connected in the passing circuit and includes a plurality of filters connected in parallel to one another. A control system is operative to produce two output signals in the passing circuit after the formant filter in sequence upon operation of the key, one of the output signals being a vowel sound and the other a consonant sound.

Abstract: A special effects circuit for use in an electronic musical instrument, preferably an electronic organ, including a filter circuit having variable bandpass characteristics and a tone source supplying a signal to the input of the filter circuit. The bandpass characteristics of the filter circuit are modified in accordance with a control signal. Upon the occurrence of an input signal, a control circuit provides the filter circuit with the control signal at a random or pseudo-random value. The instrument player may select the source of input signals from a variety of sources within the organ thereby determining the times or frequency at which the control signal changes but the value of the control signal is random or pseudo-random. The tone signal output from the filter circuit has randomly or pseudo-randomly attenuated frequency characteristics and is coupled to standard organ output circuits for audio presentation.

Abstract: A programmer for a music synthesizer including a keyboard and M independent voice modules (channels) and wherein the characteristics of each module are dependent upon K independent parameters, each parameter defined by an analog voltage level. The programmer is capable of storing N distinct programs, each program including information defining K parameters for each of M modules. The programmer is comprised of a common set of K potentiometers which are coupled through an analog to digital (A/D) converter means. The output of the A/D converter means is applied selectively either to a digital memory for storage at a location defined by operator controlled switches or through a digital to analog (D/A) converter means to the voice modules. Alternatively, information applied to the D/A converter means for application to the voice modules can be derived from the digital memory.

Abstract: A method and apparatus for introducing transient voices in an electronic musical instrument. It is the nature of some musical instruments such as a piano, harpsichord, or guitar to produce tones having a transient characteristic; however, instruments such as the trumpet, clarinet and pipe organ, which are considered to produce steady state tones, also exhibit transient characteristics at times. In general, transient effects in musical instruments can be characterized as combinations of harmonic and amplitude variations over some time period.In order to more closely synthesize the sounds of musical instruments, the present invention employs a scheme whereby a sequence of voices, which may have different harmonic and amplitude characteristics, are generated during the transient time period. This is accomplished through the use of a transient voice memory divided into "n" voice zones. Each zone may contain the same or a different voice from every other zone in the memory.

Abstract: A distortion sound effects circuit producing an output signal corresponding to an input signal but containing one of four selected types of distortion. A compressor which includes a voltage-controlled amplifier first compresses the audio input signal within preselected limits, and the distortion operations are performed on the compressed audio signal to advantageously render the subsequent distortion operations insensitive to gross amplitude fluctuations of the input signal. The compressor includes means for full-wave rectifying the compressed audio signal. The full-wave rectified signal is provided as a distorted output signal containing hard-even distortion of the type commonly achieved by severely, asymmetrically clipping a signal. A distortion circuit includes single voltage controlled square-low amplifier to which the compressed audio signal is applied performs the other three types of distortion.

Abstract: In an electronic musical instrument, the keys of a keyboard are divided into a plurality of groups by octaves, and a wave generator is provided with a memory for storing constants corresponding to musical tone frequencies to be generated according to the notes includes in a desired group out of the plurality of group, an accumulator for repeatedly adding the constants read out of the memory, and a bit position shifting circuit for shifting the bit position of the data produced by the accumulator according to the octave range of a note to be produced, thereby to obtain the data varying repeatedly according to the frequency of a note to be produced, and to reduce the storing capacity of the memory when compared to the number of keys.

Abstract: An electronic musical instrument is provided with a single controlled type signal processing circuit for processing multiplexed tone source signals corresponding to depressed keys and a circuit for preferentially selecting one of tone identifying signals corresponding to the depressed keys. The characteristic of the signal processing circuit is controlled by a tone pitch signal generated in accordance with the tone identifying signal thus selected, so as to reduce the number of a signal processing circuits.

Abstract: A tone synthesizer in which a musical tone of selected fundamental frequency is generated with a resonance effect at selected harmonics of the tone. The resonance effect is produced by adding an amplitude modulated carrier signal to the musical tone, the carrier signal being modulated by a signal having the fundamental frequency of the musical tone and the carrier frequency being an integral multiple of the fundamental.

Abstract: A tone control circuit using only one potentiometer to provide bass or treble control is described. An integrator and a differentiator are connected to the input of the circuit and their outputs to the two ends of the potentiometer. Electrical connection between the potentiometer and the input is also made to provide a flat frequency characteristic component in the output signal.

Abstract: A system for the selection and phase control of humbucking coils in electromagnetic guitar pickups to permit the musician to easily select different sounds using digital memory means for storing different combinations of gate control bits to select the pickup coils to be used, the phase of the coils selected and the output level of the selected coils combined. A three-way switch is used to count up, count down or hold a memory address for selection of a combination. The address is displayed for verification. Memories may be prestored ROMs, or alterable RAMs in which write enable control is controlled by a three-way switch. Three address counters may be provided to permit the musician to quickly select from three predetermined combinations through operation of a three-way switch.

Abstract: A keyboard type electronic musical instrument which is provided with a keyboard having an arrangement of keys corresponding to an arrangement of letter names based on the scale of the equal temperament of 12 degrees, a sound signal generator for generating sound signals of frequencies defined for the letter names, first and second gate circuit means having gate circuits respectively supplied with the sound signals from the sound signal generator, a first mixer for mixing the outputs from the gate circuits of the first gate circuit means, a frequency multiplier circuit for frequency multiplying the output from the gate circuits of the second gate circuit means, and a second mixer for mixing the outputs from the frequency multiplier circuit and the first mixer. The sound signals supplied to the gate circuits of the second gate circuit means have higher or lower frequencies than the sound signals supplied to the corresponding gate circuits of the first gate circuit means.

Abstract: A voice-controlled electronic musical instrument provides tones responsive to audible energy imparted to a microphone. An analog voltage representative of the frequency of the audible energy imparted to the microphone controls a gate signal generator. The gate signal generator decodes the analog signal into a digital word having octave and note information. The octave and note information gates operator-selected musical tones to provide a desired output signal responsive to the audible energy applied to the microphone.

Abstract: An electronic musical instrument comprises a plurality of musical tone forming systems capable of producing musical tones of different tone qualities. A priority is established between the respective musical tone forming systems and one which is of a highest priority among one or more such systems selected by a performer is automatically selected and a musical tone can be produced only from this selected system of the highest priority. The electronic musical instrument is capable also of producing musical tones from a plurality of predetermined systems simultaneously when the priority is rendered nonoperative thereby to produce an ensemble effect.

Abstract: Imitation sounds of musical instruments, especially brass wind instruments, re synthesized by using a pulse generator source driving an AGC amplifier channel having an AGC amplifier and formant filters and a limiter, the gain of the AGC amplifier being multiplicatively controlled by an instantaneously-varying control AGC signal derived from the output of the channel. The AGC signal can also be varied at the AGC point by the signal from a breath-sensing microphone in a whistle or pipe.

Abstract: The inventive circuitry extends the harmonic content of musical tones produced by a computor organ of the type disclosed in U.S. Pat. No. 3,809,786. A memory stores values of an algebraic approximation of the summation of the amplitudes of a set of Fourier components of order higher than those separately evaluated by the computor organ itself. As each musical waveshape sample point amplitude is computed by the computor organ, the stored summation approximation value for the corresponding sample point is accessed from the memory. This accessed value is appropriately scaled, and is added to the sum of the lower order Fourier component contributions that are calculated by the computor organ. The resultant sample point amplitudes are converted to musical tones in real time. In an illustrative embodiment, musical tones having the spectral content of a sawtooth wave are produced.

Abstract: Random audio signals are converted into sine-waves of corresponding frequency and duration, and harmonics are derived from the sine-waves. The harmonics are controllably attenuated and selectively inverted and combined to form an output signal. The conversion of the random signals is effected by squaring the same to drive a Schmitt trigger which feeds into a levelled integrator which leads to a diode function generator. The harmonics are generated with the use of four-quadrant multipliers.

Abstract: In an electronic musical instrument, the amplitudes of respective partial components constituting a composite waveshape at successive sample points are produced, these amplitudes are multiplied, at regular time intervals individually by coefficients each being associated with corresponding partial components to obtain the amplitudes weighted, these weighted amplitudes being accumulated successively to obtain the net amplitudes weighted of the composite waveshape for each sample point. The net amplitudes are converted to a musical sound by sounding means. The coefficients are repetitively calculated at another regular time intervals, each of which being longer than the foregoing regular time interval, by implementing the algorithm of a certain function of time, as the multiplications are carried out.

Abstract: In an electronic musical instrument, the keys of a keyboard are divided into a plurality of groups by octaves, and a wave generator is provided with a memory for storing constants corresponding to musical tone frequencies to be generated according to the notes includes in a desired group out of the plurality of group, an accumulator for repeatedly adding the constants read out of the memory, and a bit position shifting circuit for shifting the bit position of the data produced by the accumulator according to the octave range of a note to be produced, thereby to obtain the data varying repeatedly according to the frequency of a note to be produced, and to reduce the storing capacity of the memory when compared to the number of keys.

Abstract: The system comprises a frequency number memory device for storing information regarding the frequencies of respective tones, a keyboard switch for reading out frequency number information corresponding thereto from the memory device, an address generator including an adder for adding a predetermined number of the frequency number information thereby producing an address signal consisting of plural bits, address composers for processing the bits of the address signal and thereby composing digital tone signals constituting a saw-tooth, square and triangular waveshape, and digital-analog converters for converting the digital tone signals into analog tone signals, which are thereafter used to synthesize waveshapes of any tone.