Abstract: An electronic musical instrument forms output signals having at least one frequency component and an amplitude defining envelope. Output signals are formed for selected string simulators on the instrument so that the notes and chords may be formed simulating a stringed musical instrument by combining the output signals. Various parameters of the amplitude envelope of the output signals may be varied at a user's selection.

Abstract: An electronic musical instrument wherein depression of a key entails the discharge of a primary capacitor which is connected to the inverting input of an operational amplifier whose output is connected with a second capacitor serving to supply envelope control voltage signals to an analog switch which connects a tone signal generator with a tone processing unit. The extent to which the primary capacitor discharges depends on the speed of movement of the key from non-depressed to depressed position, and the intensity of residual voltage of the partially discharged primary capacitor determines the intensity of the envelope control voltage signal. The speed at which the second capacitor discharges can be regulated to produce sustain or banjo effects. The second capacitor is in series with a resistor in a feedback conduit connecting the output and the input of the operational amplifier.

Abstract: A keyboard operated musical instrument is disclosed having a portamento effect controlled from a portamento keyboard consisting of a linear array of keyswitches. The keyswitches are arranged in groups corresponding to each musical note and spaced so that a number of contiguous switches are actuated by each finger in contact with the portamento keyboard. Apparatus is provided for generating a frequency number corresponding to the closest switch actuated by the center of each finger thereby providing polyphonic portamento effects as the finger positions are slid along the portamento keyboard. An ADSR generator is used to provide envelope modulations initiated when a new finger has been detected on the slide wire and when a finger has been removed. A priority logic using frequency differences is used to distinguish between new fingers or the changes in position of a finger already in contact with the slide wire.

Abstract: An electronic musical instrument in which rhythms are each subjected to digital processing and provided uniformly with out variations in volume and tone quality and respective envelope waveshapes are given different periods of attack and decay which are obtained with the same system by calculating attack and decay coefficient for the respective rhythms on a time divided bases.

Abstract: A tone generation system is intended for use with an electronic musical instrument of the type wherein an audible tone is generated electronically in response to actuation of the instrument by a player. The invention generates digital signals capable of defining either the waveshape or the envelope or characteristic of a tone for each tone initiated by such player actuation the latter envelope being varied in accordance with the intensity of the player actuation initiating that tone. In the latter case, digital electronic circuits are utilized for developing a digital scaling signal S corresponding to the intensity of actuation of the instrument by the player, and a digital envelope signal which represents slopes and Y intercepts of portions of a composite waveform, viewed in an orthogonal coordinate system. These digital circuits arithmetically manipulate these scaling signals and envelope signals to give a composite output signal defining the envelope.This application is a continuation of application Ser.

Abstract: In a keyboard operated electronic musical instrument a detector is provided for measuring the time interval between successively actuated keyswitches. If the time interval is less than a preselected time threshold, the notes are generated with a normal ADSR envelope and if the time interval exceeds this time threshold then the notes are generated with a legato ADSR envelope. Provision is provided to accomodate variations in time when a chord is played. The system will return to the normal ADSR for time intervals greater than that for a second preselected time threshold for notes played with large time separations. The same control signals are provided to control other musical effects such as tone selection, vibrato and portamento.

Abstract: An electronic tone generator capable of providing improved musical and tone quality by providing a primary melody and a secondary melody such as an accompaniment or the like is provided. The electronic tone generator of the instant invention is characterized by the use of a primary electronic scale generator circuit for producing a primary scale signal representative of a primary melody scale and a secondary electronic scale generator circuit for producing a secondary scale signal that is representative of a secondary melody and that is distinct from the primary scale signal. The primary scale signal and second scale signal are respectively shaped and summed and thereafter applied to an electro-acoustic transducer in order to produce music having a primary melody and secondary melody of considerable musical quality.

Abstract: An MOS integrated organ circuit compensates an audio frequency signal for variations in amplitude, attack and decay characteristics caused by process variations by adjusting a single variable reference voltage. The circuit intrinsically provides for the tracking of these characteristics, such that the attack and decay characteristics are calibrated by adjusting the variable reference voltage to provide a specified amplitude characteristic.

Abstract: A circuit for generating alternating repeat keying signals in an electronic keyboard musical instrument includes a clock, a logic circuit responsive to the keys of the instrument and to the clock for producing an alternating sequence of logic signals corresponding to each of the keys, the phase of the sequence corresponding to each undepressed key being the same as the phase of the sequence corresponding to the previous key and the phase of the sequence corresponding to each depressed key being opposite that of the phase of the sequence corresponding to the previous key and a plurality of output gates each developing a keying signal in response to the depression of a respective one of the keys and the logic signals of the corresponding sequence assuming a predetermined state.

Abstract: An improved envelope generator circuit for an electronic organ provides a musically correct attack rate, i.e., the volume of a musical note is increased by an equal number of decibels for equal increments of time. The envelope generating circuit comprises a constant current source for charging a capacitor to generate a linearly increasing voltage signal upon the initial activation of any one or more keys of an electronic organ keyboard. A regulator circuit comprising an operational amplifier and a matched pair of transistors with one transistor connected into the feedback path for the operational amplifier generates an anti-logarithmic control signal in response to the linearly increasing voltage signal. The antilogarithmic control signal is used to control the amplification of a controlled amplifier to which music signals from the organ are passed.

Abstract: Most of the circuitry of an electronic organ is made up of a plurality of digital large scale integrated (LSI) circuit chips. Certain of the chips can be duplicated or substituted for others of like type to provide an organ with more or less tone generators, more or less features, etc., whereby organs of various price levels can be constructed from the same basic parts. In operation, essentially all of the organ functions and features are provided by carrying out logical and arithmetic operations on digital pulse trains generated under control of a master clock.

Abstract: An electronic organ apparatus arranged to provide percussive musical tones by differentiating a rectangular waveform tone signal and subsequently clipping the differentiated signal at a variable level under the control of an envelope signal to produce an improved percussive sound envelope. The time constant of the differentiator may be varied to vary the output sound. The output sound may be controlled by concurrently varying the level of clipping of the differentiated tone signal and varying the time constant of the differentiator. Voicing filters and other modifying inputs may be utilized for further controlling the character of the output sound.

Abstract: There is disclosed herein a music synthesizer which responds to a music note played by a music instrument. The synthesizer has an envelope generator which generates a control signal in relation to the input signal to control the loudness of the synthesized note. Also, the synthesizer has a pair of voltage controlled oscillators, one of which provides a signal having a frequency related to the frequency of the input note, and the other of which provides a signal having a frequency related to the frequency of the input signal offset by the ratio of the difference between a programmed note and a referenced note, such as A440. The programmed note is that note following the operation of a control switch. The synthesizer further includes a series of footpads which control various functions of the synthesizer, such as programming the programmed note, to allow the user to control the synthesized sound while playing an instrument.

Abstract: In a control waveform generator for an electronic musical instrument of the type wherein the generator generates a control waveform adapted to control at least one of a tone pitch, a tone color and a tone volume, the control waveform generator is constituted by a pulse generator for generating a pulse signal having a repetitive frequency, and a detector including a counter which starts to count the number of the pulse signals when a key is depressed. The detector generates a first detection signal during an interval between depression of the key and a time at which a counter reaches a predetermined value and then produces a second detection signal until the depressed key is released.

Abstract: A touch responsive tonal envelope waveshape control system is provided for an electronic musical instrument which includes cooperating tone generating and keying circuits which are responsive to actuation of a key for initiating the generation and keying of a corresponding tone. The system of the invention includes encoding circuits responsive to the actuation of a key for producing encoded signals corresponding to the intensity of player actuation of the key and an amplitude control circuit responsive to these encoded intensity signals and cooperative with the keying circuits for controlling the peak amplitude of the tonal envelope waveshape in accordance with the intensity of player actuation of the key for initiating that tone.

Abstract: An integrated keyer system for use in electronic organs comprising a plurality of discrete integrated circuit chips each corresponding to two adjacent octaves of the keyboard and connected in series to accommodate the entire keyboard. The keyer system is adapted for use in multiplexed systems wherein the keyswitch closure information is encoded in a time division multiplexed data stream fed through a plurality of the keyer chips, which are connected in series. Each of the keyer chips includes a plurality of tone inputs and outputs and a divide-by-four circuit for lowering the tones in by two octaves. The keyer chips also include serial data inputs and outputs and a demultiplexer for demultiplexing the serial data stream at the serial data input to produce a plurality of control signals corresponding to keydown signals in the serial data stream, which are fed to the individual keyers.

Abstract: In an electronic musical instrument, two or more pulse signals different in phase are generated each having a frequency corresponding to the tonal pitch of an operated key, an envelope waveshape is read out upon every key operation, sampling is executed on the envelope waveshape by means of these pulse signals, and polarities of sample values are converted in reference to these pulse signals for generation of a corresponding musical tone waveshape. Minimized use of arithmetic circuits such as adders and multipliers greatly reduces production cost whilst assuring generation of a wide variety of colorful, noise-free musical tones. By addition of a slope conversion circuit, abrupt shift in the generated musical tone waveshapes can well be disappeared.

Abstract: An electronic musical instrument comprises a key on-off memory for storing the on-off state of the respective keys, and at a time counter for counting the lapse of time after release of the respective keys. The time counter inhibits generation of the musical tone signal corresponding to the key when the conditions that predetermined time is elapsed after the key release and that the key-off state is stored in the memory are satisfied. This inhibition is separately conducted with respect to the keys. Thus, it can remarkably prevent noise when the tone should not be produced.

Abstract: There is disclosed herein a music synthesizer which responds to a music note played by a music instrument. The synthesizer has an envelope generator which generates a control signal in relation to the input signal to control the loudness of the synthesized note. Also, the synthesizer has a pair of voltage controlled oscillators, one of which provides a signal having a frequency related to the frequency of the input note, and the other of which provides a signal having a frequency related to the frequency of the input signal offset by the ratio of the difference between a programmed note and a referenced note, such as A440. The programmed note is that note following the operation of a control switch. The synthesizer further includes a series of footpads which control various functions of the synthesizer, such as programming the programmed note, to allow the user to control the synthesized sound while playing an instrument.

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 envelope is imposed on a sequence of binary waveform samples representing a musical waveform signal by repetitively summing selected ones of a group of scaled representations of each of the waveform samples of the form A/2.sup.m, A/2.sup.m+1 . . . A/2.sup.m+p, where A represents the magnitude of the waveform sample, p is a predetermined integer, and m is an integer changing by a factor of unity each time a predetermined number of the groups have been developed. The sum of each group of scaled representations differs from the sum of the preceding group by the factor A/2.sup.m+p whereby a staircase signal is produced amplitude modulating the musical waveform signal, the step size of the staircase signal charging each time said predetermined number of groups have been developed.

Abstract: A keying system provides selectable decay times for individual frequency components of a tone to be generated by an electronic organ having a top octave generator producing a multiplicity of rectangular wave signals, and a plurality of associated divider circuits. The keying system comprises a keying block having a plurality of keyer sections. Each keyer section has a first keyer channel comprising at least two MOSFET transistors which are connected in series. At least one keying section further comprises a second keyer channel similar to the first keyer channel, a voltage threshold circuit which has a selectable threshold and switching circuitry to select output signals from either the first or second keyer channel of the one keying section. Each channel of the keying block is connected between a supply voltage and a load resistor which is in turn connected to a reference potential.

Abstract: A keying system provides selectable decay times for individual components of a tone to be generated by an electronic organ having a top octave generator producing a multiplicity of rectangular wave signals, and a plurality of associated divider circuits. The keying system comprises a keyer block having a plurality of identical keying sections. Each keying section comprises at least two MOSFET transistors which are connected in series and the series combination is connected between a supply voltage and a load resistor. A multiple position switch is connected to each load resistor to selectively connect the load resistor to one of a plurality of biasing voltage supplies. Rectangular wave signals from the top octave generator and divider circuits are applied to the gate of one of the transistors in each of the identical keying sections of the keyer block.

Abstract: A harmony authorization detector (HAD) synthesizer electronically generates single audible musical notes in harmony with single original aural notes of a melody as the melody is played on an instrument by a single player. Thus the HAD functions as, in effect, a second instrument electronically operational in harmony with a manually played lead instrument. The HAD synthesizer is particularly useful with guitars although not so limited. When a lead electronic guitar is used in a solo situation playing one original note at a time, the HAD synthesizer will, for each string on each position of the guitar and with the aid of a group of tone decoders, electronically detect the single fundamental note played by the guitarist and will authorize the emission of a preset, predetermined electronically generated synthesized single harmony note e.g. a third, fifth, seventh, etc. based on the fundamental of the single note played by the lead guitarist.

Abstract: An electronic sound generator is developed for generating a sound similar to that of ANGKLONG (Indonesian terms), which comprises a circuit for generating a series of consequtive rectangular waves. A plurality of envelope wave generation circuits each produce an envelope wave having the same repeating cycle as that of each said rectangular wave and, one or more sound source circuits are used for generating signals substantially equal to the output waves of angklong, circuits in each of which an output of a sound source circuit is modulated by the relevant envelop wave. A loudspeaker sounds the modulated signal as a musical sound. In a record embodiment the sound generator further comprises a first gate to which the modulated signal is directly applied, a second gate is connected in series with the volume and/or tone control circuit, means for opening said first and second gates alternatively and a means for combining the outputs of said first and second gates to provide a musical sound from the loudspeaker.

Abstract: An envelope signal generator which has a key depression/release signal generator for producing different output levels in response to key depression and key release, a switching circuit which is set to a first output level upon key depression and set to a second output level when the stored output level of an analog memory has reached a certain value, a preset circuit for outputting at least a level setting voltage and first and second time constant setting voltages relating to an envelope, a priority selector which is supplied with the key depression/release signal generator output, the switching circuit output and the level setting voltage and selects them in a predetermined order of priority, a first circuit for converting into a current the output from a voltage controlled amplifier supplied with the analog memory output and controlled by the first time constant setting voltage, a second circuit for converting into a current the output from a voltage controlled amplifier supplied with the analog memory ou

Abstract: An electronic clock with a chime system has exclusively electronic processing for production of a variety of tone signal sequences consisting of known melodies or portions thereof and time-identifying sequences of strokes. The characteristic values of these tone signal sequences are loaded into a ROM memory and can be recalled, as required, by electronic control and release circuits at each quarter, half, three quarter or full hour. The amplitude of the audio output signals is automatically controlled in accordance with the time of day.

Abstract: A function generator of time-dependent variable type especially suitable for use as an envelope waveshape generator of an electronic musical instrument is constituted by means for setting multi-bit digitalized information which represents time information in terms of a logarithm, dividing means for dividing the bits of the time information into upper order bits and lower order bits at a bit of a predetermined order, means for converting a portion of the information represented by the lower order bits into linear information, a timing pulse generator which produces a timing pulse having a period corresponding to a value obtained by converting a portion of the information represented by the higher order bits into a natural number, and an accumulator for accumulating the output produced by the information converting means at a period of the timing pulse thereby producing an accumulated value as the time function waveshape which varies with time at a rate corresponding to the time information.

Abstract: An electronic musical instrument having an automatic performance device includes a memory storing in addition to automatic performance data, envelope control data for controlling envelopes of automatic performance tones to be generated. The envelope control data has two logical values and is used for controlling the envelope of the tone at the decaying portion. The value "0" designates a gradual decay and the value "1" designates a quick decay. The automatic performance tones are respectively imparted with either of the gradual and the quick decay shapes suitable for the time intervals between the generated tones in the designated automatic performance pattern.

Abstract: A musical waveshape processing system for an electronic musical instrument in which time-division time slots are set corresponding to a plurality of channels for producing notes selected on keyboards of the electronic musical instrument and the notes are each produced by repeatedly calculating the musical waveshape amplitude value of each channel in each time-division time slot. A musical waveshape calculator is provided which calculates the musical waveshape amplitude value as f(t)=at.sup.2 +bt+c based on waveshape data a, b and c and address information t. A multiplier is provided by which the value of an envelope synchronized with the time-division time slot is multiplied by the waveshape data a, b and c.

Abstract: In a modular, expandable organ system comprising a plurality of large scale integrated circuit (LSI) chips an LSI chip is provided which produces chord and bass frequency generation and identification. It automatically coordinates with another chip in rhythm production. It incorporates frequency generators, identifies a chord played, and provides keyers for chord notes.

Abstract: In a digital electronic organ or the like external waves of controllable duty cycle are used to control the on time of a field effect transistor (FET) through which a capacitor is charged. A similar rectangular wave of controllable duty cycle is applied to a second FET to control the on time thereof for controlling the discharge of said capacitor. The state of charge of said capacitor is used to control the conductivity of yet another FET through which a desired frequency is conducted to effect enveloping of such frequency with the desired attack and decay characteristics.

Abstract: An electronic musical instrument using continuous tone generators capable of simulating the sounds of a conventional acoustical piano. The instrument includes a gating circuit featuring a timed switch travel circuit having a double-time constant for improved control of the dynamic range from the keyboard, and a soft pedal controlling the keying voltage to produce more realistic emulation of the dynamic effects of an acoustical piano. The gating circuit produces a double-time-constant envelope of nearly harmonically related signals for a more realistic piano timbre. The tone spectrum is also controlled as a function of signal level by means of a resistor matrix feeding selected inputs of an active ladder filter, in order to reproduce timbre variation with dynamic level.

Abstract: An electronic musical instrument is provided with a keyboard which may comprise one or more keyboard sections. Plural instrument voices are stored in memory for each section of the instrument keyboard. Each stored voice comprises a set of plural multiple bit digital words. A composite audible tone corresponding to an active key comprises varying combinations of component signals derived from the stored voices. The decay pattern of the composite audible tone is divided into successive time zones. The durations of the zones may vary. For each zone, the amplitude of at least one of the component signals of the composite tone is caused to decay while the amplitudes of the remaining component signals are either not modulated or are maintained at zero. The rate of decay of the amplitude of a component signal, hence the duration of a particular time zone, may be made a function of the keyboard section associated with the active key. In an alternative embodiment, the instrument voices are not stored in memory.

Abstract: An electronic musical instrument which produces musical notes synthesized based on logic orthogonal functions stored in digital form. A coefficient corresponding to a tone selected by a tone selector is read out of a memory to calculate a logic orthogonal function, for example, a composite coefficient of a Walsh Hadamard matrix. The composite coefficient is applied to a plurality of waveshape calculators to calculate the amplitude value of a waveshape of the required tone and the waveshape calculators are actuated at the timing predetermined times the period of the musical note selected by the depressed key. Any desired musical waveshape can be produced by setting the coefficient corresponding thereto and the spectral structure of the waveshape can be changed with the lapse of time. Polyphonic tone synthesis is achieved by intermittent operation of the waveshape calculators to produce a wide variety of musical sounds. Further, a depressed key data detector is provided for detecting non-encoded key data.

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: A brass pulse keyer for electronic instruments such as electronic organs wherein the tone during attack is both amplitude modulated and pulse width modulated. The keyer is adapted for large scale integration and comprises a timing capacitor, an electronic switch connected between a source of charging potential and a capacitor and having a control terminal which is connected to the tone input, and a second electronic switch connected in series with the charge voltage, the first switch, and the capacitor and having a control terminal connected to receive the keying envelope. A comparator compares the potential on the capacitor with a reference potential and disables a gating circuit when a compare condition is reached such that the duty cycle may be controlled. As the keying envelope continues towards its maximum, the duty cycle decreases so that a more brilliant tone is achieved.

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 keying system in an electrocin musical instrument comprises a circuit for generating harmonic level control voltages for controlling the levels respectively of harmonics (inclusive of the first harmonic, i.e.

Abstract: In an electronic musical instrument of a keyboard type wherein waveshapes with different tone colors read out from waveshape memories are mixed together at a mixing ratio according to a control signal and the resultant signal is converted to a corresponding musical tone, the control signal is varied with lapse of time and also is controllable in response to the initial speed at which a key of the keyboard is depressed and to the strength of pressure of the key being depressed, in addition to time lapse. Thus, the pattern of tone variation can be variously controlled.

Abstract: A musical tone varying in tone color with the lapse of time is produced in an electronic musical instrument by retrieving a plurality of different waveshapes from a plurality of memories and then by mixing these retrieved waveshapes at a variable ratio according to a plurality of time-dependent parameters. In order to ensure a simpler arrangement of the instrument while maintaining richness in tone color variation characteristics of the produced musical tone, the mixing is adapted to be performed by carrying out multiplications individually on the respective retrieved waveshapes with the associated time-dependent parameters and then by adding up the resultant values to obtain the aimed musical tone. Some of the time-dependent parameters may be derived from other time-dependent parameter in the mixing procedure of several different waveshapes.

Abstract: In a keyboard electronic musical instrument of waveshape memory type wherein different waveshapes read out from memories are mixed together at a variable mixing ratio according to variable parameters and then converted to a musical tone, the variable parameters are calculated on the basis of information associated with both lapse of time and the pitch of a musical tone to be produced. Thus, with this musical instrument, it is possible to produce a musical tone varying in the content of higher harmonics with respect to the pitch of the tone assigned to a depressed key and in tone color according to lapse of time.

Abstract: An electronic tone generator of a type in which an audio signal of controlled waveform is generated from a stored master data list of digitally coded words incorporates apparatus for changing the harmonic structure of the waveform with time during the generation of the audio signal. The master data list is computed by generating two data lists of words defining different waveforms and multiplying the two lists together repeatedly while shifting one list relative to the other list by at least one word. The resulting master data list changes with each multiplication following a shift, producing a changing waveform in which the musical frequencies are harmonically related, the waveshape being free of intermodulation distortion.

Abstract: An electronic musical instrument is provided with an upper, a lower and a pedal keyboards and musical tone generating circuits dependently corresponding to respective keyboards and, in addition thereto, an auxiliary musical tone generating circuit which is independent of the keyboards and can be selectively coupled with a particular keyboard according to the designation by a keyboard selection switch. This auxiliary musical tone generating circuit produces tone signals having a particular tone color. Key codes for a selected one of the keyboards among key codes supplied by a channel assignment circuit are latched separately in the auxiliary circuit, and musical tones corresponding to the latched key codes are produced in this particular tone color.

Abstract: An integrated keyer system for use in electronic organs comprising a plurality of discrete integrated circuit chips each corresponding to two adjacent octaves of the keyboard and connected in series to accommodate the entire keyboard. The keyer system is adapted for use in multiplexed systems wherein the keyswitch closure information is encoded in a time division multiplexed data stream fed through a plurality of the keyer chips, which are connected in series. Each of the keyer chips includes a plurality of tone inputs and outputs and a divide-by-four circuit for lowering the tones in by two octaves. The keyer chips also include serial data inputs and outputs and a demultiplexer for demultiplexing the serial data stream at the serial data input to produce a plurality of control signals corresponding to keydown signals in the serial data stream, which are fed to the individual keyers.

Abstract: The electronic musical instrument is provided with a plurality of musical tone generating channels of a number smaller than that of the keys and a channel processor for randomly assigning key information representing depressed keys to the musical tone generating channels. Furthermore the musical elements including the pitch, the tone color and the envelope of the musical tones generated by respective channels are made to be different thereby imparting a random property (casualness) to the generated musical tone.

Abstract: In a musical keyboard instrument of a type having a number of tone generators substantially less than the number of keys, one of the tone generators being assigned to a key when activated, the pitch of the tone generator being set by the particular key, apparatus is provided for maintaining a constant audible loudness level to the listener from the tone generator regardless of the pitch of the tone generator. A plurality of sets of amplitude values are stored in a memory, each set including one value for each key. Each set of values corresponds to a particular loudness level. The envelope amplitude of the tone generator output is controlled to produce the same loudness level for all notes by addressing a set of values according to the selected loudness level and addressing a particular value according to which key is activated. An amplitude value is selected which is then used to control the envelope amplitude of the tone generator output signal.

Abstract: The present invention is a two-part apparatus for producing note attack and decay in a conventional electronic musical instrument. Either part of the invention may be used independently of the other; however, at present the combined use is preferred. In part one, there is provided an eight state counter clocked at a rate equal to the note generator cycle and a digital magnitude comparator. The inputs (A) from the eight state counter are compared to the attack and decay scale factor inputs (B) by the comparator. The A>B,A=B functions are generated by the comparator in combination with an OR gate. The OR gate output and the sample gating signal from the conventional musical instrument are applied to an AND gate which outputs a modulated sample gating signal. In part two, the modulated sample gating signal of part one is subpulsed individually by two subpulses.

Abstract: A brass keyer system for an electronic organ wherein the keyboard is multiplexed to produce a polyphonic serial data stream, which is then converted to a monophonic serial data stream containing a keydown signal in a time slot corresponding to the highest note played on the keyboard. The monophonic data stream is converted to a multiple bit binary word that is used by the tone generation and keying portion of the system to produce a rectangular wave tone corresponding in frequency to the highest depressed key and having amplitude and pulse width modulation on attack and decay so as to produce a brass tone. The monophonic serial data stream is demultiplexed by means of a recirculating delay loop which repetitively recirculates the keydown pulse for the depressed key. The number of recirculations of this pulse are counted by a first counter and the position of the pulse within the delay loop is registered by a second counter, which is synchronized with the multiplexer.

Abstract: An envelope generator comprises a counting circuit and counting control means capable of controlling a counting mode of the counting circuit, i.e., operation and non-operation of the counting circuit, counting speed, addition and subtraction etc., in accordance with an envelope shape to be obtained. There are various predetermined counting modes corresponding to different envelope shapes and the envelope generator includes selection means for causing the counting control means to select a desired one of the counting modes.