Abstract: A method and apparatus for generating a simulated reverberation characteristic in an input audio signal having a plurality of channels, each channel transmitting time-synchronized data elements. The method and apparatus imparts a unique delay to each element of a set of time-synchronized data elements and thereafter delays the data element set through a series of delay elements. Each of a plurality of early reflection taps reads in and outputs a unique linear combination of the delayed data elements. The delayed elements are selectively input to at least one summing filter incorporating a plurality of comb filters. The output of the at least one summing filter is selectively combined based upon a summing scheme to provide a plurality of sum output elements. The sum output elements are combined with the early reflection tap output and a preselected combination of the time-synchronized data elements of the input signal to create a simulated reverberation signal.

Abstract: The present invention provides an apparatus and method for phase synchronizing tones in an electronic musical instrument. The apparatus includes a microprocessor having an input for receiving a signal representative of a selected note whereupon receipt of the signal, the microprocessor checks a set of available ranks to determine which of the available ranks is associated with the selected note. The apparatus further includes an oscillator which is established for each rank determined to be associated with the selected note such that each oscillator includes initializing parameters and initiating parameters which define the selected note and the associated rank. The apparatus also includes a plurality of tone engines for generating tones.

Abstract: An apparatus for achieving the effect of air movement in instruments during replication and sounding of complex musical instruments by separating unstable frequency components, the quasi-periodic components, from stable fundamental and harmonic components, the periodic components, of compound voice waveforms, storing the respective component information pertaining to the quasi-periodic and periodic components in separate memory locations, and recombining the quasi-periodic component with one or more periodic components in appropriate fashion to form and sound the compound voice waveforms.

Abstract: A method for achieving the effect of air movement in instruments during replication and sounding of complex musical instruments by separating unstable frequency components, the quasi-periodic components, from stable fundamental and harmonic components, the periodic components, of compound voice waveforms, storing the respective component information pertaining to the quasi-periodic and periodic components in separate memory locations, and recombining the quasi-periodic component with one or more periodic components in appropriate fashion to form and sound the compound voice waveforms.

Abstract: An automatic playing device for a musical instrument includes a memory unit which stores a plurality of discrete states, e.g., patterns of key actuation of a keyboard, which can be serialized and combined with or substituted for manual keying information from a keyboard or other control device. Combining and substituting are controlled by the actuation of one or more switches by a human operator. The operator can advance through the stored pattern by actuating a single key or by playing a simple sequence of notes on a keyboard.

Abstract: A touch sensitive system for an electronic musical instrument providing a multiple key switch contact system for effecting control over two or more tone generating systems. The first tone generating system operating rapidly in response to the actuation of the key switch to produce a desired voice. The second or subsequent tone generating systems operate sequentially in a delayed manner on the actuation of the key switch effecting a predetermined delay in the production of the desired voice. The audio output of each of the tone generating systems is summed forming a resultant waveform for audio amplification. The key switch actuation, depression and release, causes the tone generating systems to respond immediately to the depression or release of the key switch which effects a change in the envelope characteristics of the resultant waveform.

Abstract: A method and apparatus for reproducing the complete attack transient and steady state portions of a waveform is disclosed.

Abstract: A key action for an electronic musical instrument for simulating a mechanical-type tracker action having a single means embodying an electrical contact means and a motion retarding means to cause a toggling of the key while the electrical contact is maintained.

Abstract: A method and apparatus for interpolating between the harmonic structures of a waveform stored in memory during portions or the entire transient periods of said waveform. In an electronic musical instrument having a greater number of selectively actuable switches than note generators to cause the production of sounds corresponding to the respective notes of a musical scale, the present invention interpolates between the harmonic structures of a waveform stored in memory during portions or the entire transient periods of said waveform. This is accomplished through the use of memory units having a number of locations or zones within each memory where the number of zones is equivalent to the number of discrete harmonic structures.

Abstract: The string snub effect functions so as to introduce a different set of parameters for the harmonic content, envelope amplitude, shape and rate of decay and pitch of the resulting sound upon key release when a percussive string-type voice is selected in an electronic musical instrument. The apparatus for causing a snubbing of the resulting tone comprises a means for selecting a percussive string-type waveform and for generating a signal indicative of such selection, a means for detecting the release of a depressed key and the presence of the signal indicative of the selection of a percussive string-type waveform and for generating a signal indicative of such detection, a means for halting further interpolation of the selected waveform and switching to a preselected harmonic structure of said selected waveform, means for shifting the pitch of the generated tone of said selected waveform, and means for variably controlling the envelope amplitude, shape and rate of decay of the selected waveform.

Abstract: A keyboard teaching device for the self-instruction of a student of keyboard musical instruments is provided which enables the student to correlate the positions of the keys on a musical instrument keyboard with the positions of the notes on a musical scale. A keyboard having a plurality of keys corresponding to the notes of a musical scale for generating a first set of control signals in an initialization or set-up mode and key-note correlation signals in an instruction or game mode, at least one storage means having a predetermined combination of logical signals providing a source for a random sequence of one or more notes over a predetermined range in the game mode for generating a second set of control signals in response to the actuation of one or more keys in either mode and a means for generating audio tones and displaying video images in accordance with the first and second sets of control signals enables the student to visually and audibly check his or her selection of one or more of the keys.

Abstract: In an electronic musical instrument having at least one keyboard with keys corresponding to the notes of a musical scale apparatus for controlling the dynamic frequency modulation of tones reproduced from key pulses associated with active keys of the keyboard including a tonal effect control for selecting one of the desired modulation effects, vibrato, delayed vibrato or decayed vibrato, a multiplexed counter having a plurality of distinct sequential time periods for creating a delay proportional to its counting rate for generating output signals for controlling the time variant parameters of the modulation effects, a triggering means for initiating individually a count in each of the time periods of the counter in response to the generation of a key pulse, at least one count source for controlling the counting rate of the counter, a comparator for disabling the count in any of the time periods of the counter and timing alignment means for realigning the output signals of the counter with the corresponding ke

Abstract: A digital electronic organ mixture system comprises a pair of digital organs operatively connected in parallel to the same keyboard or keyboards. The keys are grouped into regions of adjacent keys. In one of the parallel organ systems, the frequency numbers ascend along the keyboard corresponding to the notes associated with the keys. In the other parallel organ system, the frequency numbers are weighted by preselected factors, the factor being the same for each keyboard region, and the factor for each successive region along the keyboard being lower than the factor for the immediately preceding region. Activation of a key along the keyboard produces a pitch series comprising a note produced by the unweighted frequency numbers in one organ system and a second note produced by the weighted frequency numbers in the other organ system. The pitch series breaks back at each successive keyboard region in accordance with the weighting factor for that region.

Abstract: A method and apparatus for interpolating between the harmonic structures of a waveform stored in memory during the transient periods of said waveform. In an electronic musical instrument having a greater number of selectively actuable switches than generators to cause the production of sound corresponding to the respective notes of the musical scale the present invention interpolates between the harmonic structures of a waveform stored in memory during the transient period of that waveform. This is accomplished through the use of memory units having a number of locations or zones within each memory where the number of zones is equivalent to the number of discrete harmonic structures. The first of the memory units contains a discrete fixed harmonic structure in each of its zones, and a second of the memory units contains a difference value in each of its zones where the difference value is equal to the difference between the discrete fixed harmonic structure in adjacent zones of the first memory.

Abstract: An asynchronous interface includes two memories which store multiplexed keyboard information such that while one memory is writing in newly acquired key information from one musical instrument system at the clock rate of that system, the other memory is reading out previously acquired key information to a second musical instrument system at the clock rate of the second system. Periodically, based on timing signals derived from both systems, the read/write roles of the two memories are reversed. Any number of asynchronously clocked systems, each connected to an associated asynchronous interface, may be keyed by a single key multiplexing device or by the multiplexing information from another asynchronous interface.

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: 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: In a digital musical instrument, timbre modulation is effected through the use of a digital magnitude comparator and associated digital logic. Selected note frequency signals and selected scale factors are compared in the digital magnitude comparator. Selected comparator outputs are applied to the associated digital logic in conjunction with a sample gating signal. This modulation results in a segmentation of the audio waveshape in accordance with the frequency signals selected for use in the comparator. Hence, choice of lower pitched frequency signals will result in a wider segmentation period, while choice of higher pitched frequency signals will narrow the segmentation period. Timbre modulation may be employed during note attack and/or decay.

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 programmable voice characteristic memory system for programming any number of different specifications in an electronic digital organ. Digital information which defines voice characteristics in an electronic digital organ is stored in a read-write specification memory. Voice characteristic information may be selectively written into the specification memory from an external data inputting device such as a punched card reader or from an external non-volatile read-write memory such as a magnetic tape. Information stored in the specification memory may be transferred to and recorded on the external non-volatile read-write memory for permanent storage and future use. Voice characteristic information stored in the specification memory may also be accessed by the digital organ to generate musical tones in conventional fashion.