Abstract: Tone generating processing is executed on an operating system having no full multitask function. The tone generating processing is activated a plurality of times, i.e., at a plurality of activating times, within each predetermined time period. Thus, even when the tone generating processing fails to be activated at some of the activating times, a predetermined number of samples of tone data can be belatedly formed within the predetermined time period, by tone data forming operations being effected only at the other activating times when the tone generating processing is actually activated.

Abstract: An electric instrument amplifier emulates an audio characteristics of a traditional vacuum-tube type amplifier. The electric instrument amplifier is formed in a single housing for amplifying an audio signal from an electric instrument. The electric instrument amplifier includes an A/D (analog-to-digital) converter for converting a first analog signal from the electric instrument to a digital signal, a digital signal processing circuit for processing the digital signal to add an intended effect to the digital signal, a D/A (digital-to-analog) converter for converting the digital signal processed by the digital signal processing circuit to a second analog signal, a tube amplifier having at least one vacuum-tube for amplifying the second analog signal, and a virtual power circuit formed with semiconductor devices for amplifying or attenuating an audio signal produced by the tube amplifier.

Abstract: A method and apparatus for generating musical tones are provided. Musical tones are generated based on musical tone waveform samples generated through a plurality of channels, and performance information is input. Control information is input depending on an amount of operation of an operating element operated by a user. Musical tone waveform samples are generated for each of the channels corresponding to the performance information input within a predetermined time period, in a number corresponding to the input control information, whenever the predetermined time period elapses. Musical tones are generated based on the generated musical tone waveform samples.

Abstract: A method and apparatus for generating musical tones are provided. Musical tones are generated based on musical tone waveform samples generated through a plurality of channels, and performance information is input. Control information is input depending on an amount of operation of an operating element operated by a user. Musical tone waveform samples are generated for each of the channels corresponding to the performance information input within a predetermined time period, in a number corresponding to the input control information, whenever the predetermined time period elapses. Musical tones are generated based on the generated musical tone waveform samples.

Abstract: A music apparatus is constructed for processing a music tone signal in response to a clock signal at each sampling period. In the music apparatus, a clock generator generates the clock signal. A signal processor is operable in synchronization to the clock signal for time-divisionally processing a plurality of music tone signals through a plurality of channels within one sampling period. A clock controller is operative during a supply duration allocated within one sampling period for supplying the clock signal to the signal processor from the clock generator to thereby operate the signal processor, and is operative during other than the supply duration within one sampling period for stopping the supplying of the clock signal to the signal processor to thereby suspend the signal processor.

Abstract: Tone generating processing is executed on an operating system having no full multitask function. The tone generating processing is activated a plurality of times, i.e., at a plurality of activating times, within each predetermined time period. Thus; even when the tone generating processing fails to be activated at some of the activating times, a predetermined number of samples of tone data can be belatedly formed within the predetermined time period, by tone data forming operations being effected only at the other activating times when the tone generating processing is actually activated.

Abstract: An apparatus (10) for processing at least one analogue audio signal, including means (24) for receiving a first analogue audio signal, means (48) for converting said first analogue signal into a first digital signal, means for comparing said first digital signal with data representing musical notes, means (44) for selecting a datum representing a reference musical note from said data representing musical notes on the basis of result of comparing said first digital signal with said data representing musical notes, means (62) for converting said datum into a second analogue audio signal, means (28) for outputting said second analogue audio signal, and means (32) for visually representing said second analogue audio signal.

Abstract: Tone generating processing is executed on an operating system having no full multitask function. The tone generating processing is activated a plurality of times, i.e., at a plurality of activating times, within each predetermined time period. Thus, even when the tone generating processing fails to be activated at some of the activating times, a predetermined number of samples of tone data can be belatedly formed within the predetermined time period, by tone data forming operations being effected only at the other activating times when the tone generating processing is actually activated.

Abstract: Sample data stored in a storage device, such as a hard disk, are sequentially read out and transferred to a buffer memory, and the sample data are read out from the buffer memory, one sample per sampling period. Sample data at addresses of the buffer memory, where sample data read out has been completed, are sequentially updated with sample data newly read out from the storage device. Jump-from address and jump-to address are set while the sample data are being read out, sample by sample, from the buffer memory. When the read address of the buffer memory reaches the set jump-from address, the read address of the buffer memory is caused to jump to the jump-to address to carry on reading out the sample data from the jump-to address onward. Such readout control for the address jump is used for reproduction of silent data and repetitive sound.

Abstract: A remix apparatus and a remix method are provided, which can generate new musical tone pattern data with new tempo and groove while partly maintaining the tempo and groove of the original musical tone pattern data. Musical tone pattern data having a first predetermined length are divided into a plurality of first musical tone piece data each having a second predetermined length smaller than the first predetermined length, and the musical tone pattern data are divided into second musical tone piece data each having a third predetermined length smaller than the first predetermined length and different from the second predetermined length.

Abstract: A method is designed for controlling a plurality of tone generating drivers by an integrating driver installed in an operating system to generate music tones according to performance data created by a music application software. In the method, the performance data created by the music application software is inputted into the integrating driver through an application program interface provided by the operating system. The performance data is distributed from the integrating driver to one or more of the tone generating drivers provisionally registered to the integrating driver. The registered tone generating driver is operated to generate waveform data of a music tone at a specific sampling frequency based on the distributed performance data. The waveform data is streamed back from the registered tone generating driver to the integrating driver. The specific sampling frequency of the streamed waveform data is converted into a common sampling frequency by the integrating driver.

Abstract: An acoustic signal producing apparatus wherein various musical effects are applied to a musical tone signal and an acoustic signal respectively produced at an internal tone generator and supplied from an external device such as a microphone, an electronic musical instrument or the like in such a manner that an applying state of the musical effects can be changed in accordance with various effect control parameters applied thereto.

Abstract: Wavetables for a wavetable synthesizer are divided into nonpaged and paged segments. The nonpaged segments are page locked in system memory, so that the wavetable may beginning playing when referenced. The paged segments are paged into memory as needed, and may be paged out of memory when no longer required. The segmentation of the wavetable is determined based on the maximum data rate for the wavetable and a maximum paging delay for the system. Wavetable segmentation is automatically tuned by monitoring actual paging delays and, taking into account a margin for error, updating the value of the maximum paging delay used to determine the required size for a nonpaged wavetable segment. An aggressive margin for error may be employed where an alternative mechanism is provided for handling overruns of the nonpaged wavetable segments.

Abstract: For a given tone generating channel, tone waveform sample data corresponding to a plurality of sampling cycles (e.g., 100 samples) are arithmetically formed collectively. Once performance information such as MIDI event data is supplied to a tone generator MIDI driver from an application program such as a MIDI sequencer, the MIDI driver, in response to an input MIDI signal, assigns new tone generation to a designated tone generating channel of a tone generator task, and prepares tone controlling parameters to be set in the designated channel. The tone generator task arithmetically forms tone waveform data by use of the tone controlling parameters and passes the tone waveform data to a CODEC circuit functioning as an A/D converter. The program and a general-purpose operating system are sequenced and executed by a preemptive multitask management program. In this way, it is possible to reduce overheads involved in arithmetically forming tone waveform samples.

Abstract: A device to perform tone generation while efficiently using a broad bit width bus and essentially eliminating the delay from the request for tone expression until its expression. An arithmetic processing device that generates tones reads the data all at once from a memory in which tone data is stored. This is set so that the delay time from when there is a request for tone generation until the tone is actually generated and expressed is negligible.

Abstract: A music apparatus has a central processor, a plurality of generator modules, and a program memory storing instructions for causing the central processor to execute a process of synthesizing a musical tone signal with the generator modules. The process includes the steps of commanding each of the generator modules to generate a predetermined number of samples of the musical tone signal at a common sampling period, and collecting the samples from each of the generator modules and processing the collected samples at the common sampling period to thereby synthesize the musical tone signal. The generator modules include a synchronous generator module that does generate the predetermined number of the samples at the common sampling period, and an asynchronous generator module that does not generate the predetermined number of the samples at the common sampling period.

Abstract: A succession of performance sounds is sampled, and the sampled performance sounds are divided into a plurality of time sections of variable lengths in accordance with respective characteristics of performance expression therein, to extract waveform data of each of the time sections as an articulation element. The waveform data of each of the extracted articulation elements are analyzed in terms of a plurality of predetermined tonal factors to thereby create template data of the individual tonal factors, and the thus-created template data are stored in a data base. Tone performance to be executed is designated by a time-serial sequence of a plurality of articulation elements, in response to which the respective waveform data of the individual articulation elements are read out from the data base to thereby synthesize a tone on the basis of the waveform data. Thus, it is possible to freely execute editing, such as replacement, modification or deletion, of the element corresponding to any desired time section.

Abstract: A first microprocessor controls an actuator according to a control program stored in a program storage memory, using a learnt value stored in a learning value storage memory. The learnt value is updated in response to an action of the actuator. A second microprocessor is connected to the first microprocessor to replace the control program with another control program which also has a function to initialize the learnt value. However, when the learnt value has been updated, the first microprocessor prohibits the second microprocessor from replacing the control program, thereby preventing the impairment of control response due to initialization of the learnt value.

Abstract: Wavetables for a wavetable synthesizer are divided into nonpaged and paged segments. The nonpaged segments are page locked in system memory, so that the wavetable may beginning playing when referenced. The paged segments are paged into memory as needed, and may be paged out of memory when no longer required. The segmentation of the wavetable is determined based on the maximum data rate for the wavetable and a maximum paging delay for the system. Wavetable segmentation is automatically tuned by monitoring actual paging delays and, taking into account a margin for error, updating the value of the maximum paging delay used to determine the required size for a nonpaged wavetable segment. An aggressive margin for error may be employed where an alternative mechanism is provided for handling overruns of the nonpaged wavetable segments.

Abstract: A new method and apparatus for music synthesis is provided. A chaotic system is driven onto a periodic orbit by a compressed initialization code. A one-dimensional, periodic waveform is then produced from the periodic orbit. A variety of periodic orbits produces a variety of sounds, which sounds approximate the sounds of different musical instruments. By sampling the amplitude of the periodic waveforms over time, a digital version of the sound is produced. The frequency and duration of a note to be synthesized are produced by sampling the periodic waveform at the proper rate to produce the desired frequency and then repeating the waveform to produce a note of the required duration.

Abstract: A digital sampling instrument for multi-channel interpolatative playback of digital audio data stored in a waveform memory provides improved interpolation of musical sounds by use of a cache memory.

Abstract: During a succession of working cycles, a sound synthesizer system for obtaining at an output a series of electrical samples produces first level samples from zero level samples which can come from diverse sources. The samples are produced allowing for parameters such as the frequency, amplitude, phase or a filter coefficient. All of the data used in establishing samples is processed in cells materialized by locations of a plurality of memories. The content of the cells can evolve from one working cycle to the other and data calculation means are used on a timesharing basis for all the cells. The first level samples can be selectively combined to form second level samples before they are transferred to an output.

Abstract: Tone generator device, which is applied to a computer, has no waveform memory of its own and is connected via an extended bus to the computer having a main memory where waveform sample data are prestored. When a tone of predetermined pitch is to be reproduced, the tone generator device designates a block of a specific quantity of the waveform sample data in accordance with the pitch to be reproduced and requests that the block be read out from the main memory and burst-transmitted via the extended bus. The burst-transmitted waveform sample data are temporarily stored in an input buffer and then read out from the buffer in accordance with pitch information to generate tone waveform data of the desired pitch. The burst transmission of the data block and subsequent tone waveform data generation are carried out at high speed asynchronously with a predetermined reproduction sampling cycle. The generated tone waveform data are output via an output data in the predetermined reproduction sampling cycle.

Abstract: A signal representation method and apparatus for digital audio provides high quality low cost resampling by transferring the difficult interpolative computations into front-end (off-line) preprocessing, thereby reducing the load on the tone generating synthesis processor. This allows nearly perfect arbitrary-ratio resampling of stored waveforms at a fraction of the cost of prior art resampling. It also allows elimination of the prior art polyphase coefficient table since the waveform reconstruction information is fully contained within the polynomials. This is especially advantageous for execution on general purpose multi-tasking media processors.

Abstract: A synthesis of percussion musical instruments sounds is provided using a microprocessor (17) that implements an all pole lattice filter and applying either a single impulse signal to the filter or N samples of an excitation signal sequence to the filter by a memory (19). The coefficients of the filter are determined by storing digital samples (501) of desired musical note from a desired percussion instrument, generating a Fourier transform to get a spectrum (502), picking the peaks of the spectrum (503) to select the most prominent components in the spectrum and determining wanted frequencies for decaying sine waves and for the frequencies finding the time envelope and estimating therefrom the pole radius.

Abstract: A wavetable audio synthesis system includes a simplified burst data transmission interface and a modified wavetable data structure in a system memory to transfer wavetable data from the system memory to a wavetable audio synthesis device with reduced hardware complexity. The system memory is configured to store voice data in patches including a plurality of voice data samples beginning at an initial address and extending through a plurality of ramp voice data samples to a starting loop address. The voice data in the patches then includes a plurality of looping voice data samples from the starting loop address to an ending loop address. The voice data patches are extended by repeating the voice data samples beginning with the sample at the starting loop address and extending toward the samples at the ending loop address. The number of repeated samples extend for a number of samples equal to the size of a burst transfer.

Abstract: For use in a synthesizer having a wave source that produces a periodic wave, frequency shifting circuitry for frequency-shifting the periodic wave and waveshaping circuitry for transforming the periodic wave into a waveform containing a formant, the frequency-shifting causing displacement of the formant, a circuit for, and method of, compensating for the displacement and a synthesizer employing the circuit or the method. In one embodiment, the circuit includes bias circuitry, coupled to the wave source and the frequency shifting circuitry, that introduces a bias into the periodic wave based on a degree to which the frequency shifting circuitry frequency shifts the periodic wave, the bias reducing a degree to which the formant is correspondingly frequency-shifted.

Abstract: A nonperiodic waveform is forced to a periodic character to facilitate looping of the waveform without introducing audible, and thus objectionable, sound artifacts. Nonperiodic waveforms are typically nonperiodic due to the presence of nonharmonic high frequency spectral components. In time, the high frequency components decay faster than low frequency components and looping of the waveform is facilitated. A loop forcing process and loop forcing filter facilitate looping of a nonperiodic waveform by accelerating the removal of the nonperiodic high frequency components. A loop forcing filter accelerates the removal of nonperiodic high frequency components using a comb filter having a frequency selectivity that varies in time.

Abstract: A data compression method and apparatus for the compression of sound data utilized in digital sampling keyboard instructs. The present invention reduces memory requirements for sampled sounds without compromising sound quality, using three techniques. The third technique improves the defect of formant distortion when sampled sounds are transposed.

Abstract: A method for shifting the timbre and/or pitch of an input signal samples the input signal at a first rate and stores the samples in a memory buffer. A digital signal processor resamples the stored input signal at a rate that differs from the first rate at which the input note is originally sampled and stores the resampled input signal in a second memory buffer. A pitch shifter shifts the pitch of the input signal by periodically scaling the resampled input signal by a window function to create an output signal. The rate at which the resampled data is replicated by the window function determines the pitch of the output signal.

Abstract: In a case where tone waveform sample data are to be arithmetically formed by software, there are installed, within a virtual device driver routine of an operating system, a MIDI processing routine for converting a received MIDI event into tone generator control data and a waveform forming processing routine for arithmetically forming tone waveform sample data for one frame. The MIDI processing routine is triggered by a software interrupt signal that is generated in response to a MIDI event produced from an application software program such as a sequencer software program, and the waveform forming processing routine is triggered by a hardware interrupt signal that is generated upon completion of tone reproduction for one frame.

Abstract: An improved method for forming a timbre sample (Q sample) is described. A first Q sample is extracted. A fixed length of the first Q sample is extracted to form a first QL. A portion of the first Q sample other than the first QL is treated as a first pre-waveform. A last portion of the first pre-waveform is extracted and is processed with the second Q sample by a first COS modulation so as to obtain a second QL, which is connected to the first pre-waveform to form a second Q sample. A first period waveform of the second QL and a last portion of the first pre-waveform are processed by a second COS modulation to form a single period QL. Repeating the single period QL forms a third QL. Connecting the third QL to the first pre-waveform forms a third Q sample. The second QL is transformed by a digital Fourier transformation, and its high frequency modes are removed. The transformed second QL is inversely transformed back by an inverse digital Fourier transformation to form a fourth QL.

Abstract: A synthesizer system includes a CPU and host memory operating a software routine. The software routine stores a first part of each waveform signal in a sample pool of host memory and provides remaining portions of selected musical sounds from the hard drive to a stream cell array without an audio perceivable delay. The synthesizer system utilizes a caching system which allows low cost, high storage devices to be utilized in an audio synthesizer system. MIDI control signals are provided to an audio processor for selecting appropriate digital waveform signals.

Abstract: A method and apparatus for vocally entering acoustic data and producing an output. In one embodiment, a note preset is identified and selected according to the vocal input signal, and auxiliary note information is also extracted from the vocal input signal. The auxiliary note information is used to generate synthesis engine parameters that modify the note preset to provide a complex note output. In another embodiment, feature vectors of note segments are used to select a preset file representing a particular instrument from a library of instrument preset files. A note preset is selected from the instrument preset file according to the note segment to create an output corresponding to the selected instrument or instrument group.

Abstract: A method for shifting the timbre and/or pitch of an input signal samples the input signal at a first rate and stores the samples in a memory buffer. A digital signal processor resamples the stored input signal at a rate that differs from the first rate at which the input note is originally sampled and stores the resampled input signal in a second memory buffer. A pitch shifter shifts the pitch of the input signal by periodically scaling the resampled input signal by a window function to create an output signal. The rate at which the resampled data is replicated by the window function determines the pitch of the output signal.

Abstract: A sound source apparatus has operation blocks composed of softwares used to compute waveforms for generating a plurality of musical tones through a plurality of channels according to performance information. In the apparatus, a setting device sets an algorithm which determines a system composed of selective ones of the operation blocks systematically combined with each other to compute a waveform specific to one of the musical tones. A designating device responds to the performance information for designating one of the channels to be used for generating the musical tone. A generating device allocates the selective operation blocks to the one channel and systematically executes the allocated selective operation blocks according to the algorithm so as to compute the waveform to thereby generate the musical tone through the channel.

Abstract: In a case where tone waveform sample data are to be arithmetically formed by software, there are installed, within a virtual device driver routine of an operating system, a MIDI processing routine for converting a received MIDI event into tone generator control data and a waveform forming processing routine for arithmetically forming tone waveform sample data for one frame. The MIDI processing routine is triggered by a software interrupt signal that is generated in response to a MIDI event produced from an application software program such as a sequencer software program, and the waveform forming processing routine is triggered by a hardware interrupt signal that is generated upon completion of tone reproduction for one frame.

Abstract: A device and method is disclosed to correct intonation errors and generate vibrato in solo instruments and vocal performances in real time. The device determines the pitch of a musical note produced by voice or instrument and shifts the pitch of that note to produce a very high quality, high fidelity output. The device includes a pitch detector that automatically recognizes the pitch of musical notes quickly. The detected pitch is then used as an input to a pitch corrector that converts the pitch of the input to an output with a desired pitch. The corrected musical note is then in tune with the pitch standard. The device and method employ a microprocessor that samples the signal from a musical instrument or voice at regular intervals using an analog-to-digital converter and then utilizes data derived from an auto-correlation function of the waveform to continuously determine the period of the waveform. The period of the waveform is then compared to a desired period or periods (such as found in a scale).

Abstract: A system and method are disclosed for independently adjusting the pitch and timbre of an input signal within a modified Lent shifter. A method of adjusting the pitch and timbre of an input signal includes receiving an input signal and determining a window length corresponding to the input signal. A finite length spectrally smoothed signal is created from the input signal by synchronously windowing the input signal. The timbre of the finite length spectrally smoothed signal is adjusted thereby creating a finite length timbre adjusted signal. The finite length timbre adjusted signal is recombined at a rate necessary to produce a desired output pitch thereby reducing artifacts introduced by processing the finite length timbre adjusted signal and minimizing latency between receiving the input signal and producing a desired output signal.

Abstract: A method is provided for automatically rearranging a plurality of digital information units (DIU) arbitrarily designated in a first digital information file (DIF), each DIU containing data with artistic structure and characteristics, to create a plurality of second DIF's having different artistic structure and characteristics from the first DIF. The method includes a first process for automatically (1) reordering, (2) repeating, (3) creating alternate sequences of, (4) altering durations of, (5) including and excluding certain ones of, and (6) automatically manipulating the characteristics of the plurality of DIU.

Abstract: This invention relates to a system and method for altering the harmonic referent of segments of a music composition while maintaining the register of the musical segments and their conformity to a harmonic rule-base. By combining the three novel notions of a "role-preserving" transformation "shape-preserving" transformation, and a "register" preserving transformation, a novel operation enabled by the present invention can be described. Essentially, the invention allows a pitch to be moved from one harmonic context to another. The pitches are then constrained to take on values that have the same harmonic function as their corresponding original pitches, while remaining, as much as possible, within the same register as their corresponding original pitches. Secondly, when a group of pitches are moved together as a melody, the operation can preserve not only the function and register of the pitches but the shape of the melody.

Abstract: A waveform-data dividing device, employed by an electronic musical instrument providing a waveform memory, is used to automatically divide waveform data into registers. The device provides a division-data table in which a plurality of division data are respectively written at locations which are arranged in connection with the registers. When a new waveform is inputted so that corresponding new waveform data are stored in the waveform memory, one division data is created based on the waveform data and is written into the division-data table at the location which is determined responsive to a pitch of the waveform data. Herein, one new waveform is divided into multiple sections so that detection of pitch is performed with respect to each of the sections. When the same pitch is detected with respect to two consecutive sections, that pitch is used as the pitch representing the waveform data as a whole.

Abstract: A digital sampling instrument for multi-channel interpolatative playback of digital audio data stored in a waveform memory provides improved interpolation of musical sounds by use of a cache memory.

Abstract: For a given tone generating channel, tone waveform sample data corresponding to a plurality of sampling cycles (e.g., 100 samples) are arithmetically formed collectively. Once performance information such as MIDI event data is supplied to a tone generator MIDI driver from an application program such as a MIDI sequencer, the MIDI driver, in response to an input MIDI signal, assigns new tone generation to a designated tone generating channel of a tone generator task, and prepares tone controlling parameters to be set in the designated channel. The tone generator task arithmetically forms tone waveform data by use of the tone controlling parameters and passes the tone waveform data to a CODEC circuit functioning as an A/D converter. The program and a general-purpose operating system are sequenced and executed by a preemptive multitask management program. In this way, it is possible to reduce overheads involved in arithmetically forming tone waveform samples.

Abstract: A digital sound generating system is provided which is capable of, in addition to generating a tone (first waveform data), recording or reproducing PCM sound data representing a human voice or sound of a music piece lasting for a relatively long time (second waveform data). To this end, in the tone generating process, tone waveform sample data is read out from a waveform RAM on the basis of address data given from an address calculating section and is then output as an analog signal via an interpolating section and D/A converter. In reproduction of PCM sound data, the PCM sound data supplied via a CPU interface is transferred using the waveform RAM as a buffer and is then supplied outside of the system through a same channel as in the tone generating process. In recording of PCM sound data, a high-frequency-component removing process is performed, by a filtering calculating section, on PCM sound data received via an A/D converter so as to prevent unwanted aliasing noise.

Abstract: Apparatus for simultaneously decompressing and interpolating compressed audio data. The compressed audio data is stored in differential log format, meaning that the difference between each two consecutive data points is taken and the log of the difference calculated to form each compressed data point. To efficiently decompress and interpolate the compressed data, advantage is taken of the fact that addition of logs is equivalent to multiplication of linear values. Thus the log of an interpolation factor is added to each compressed data point prior to taking the inverse log of the sum. An integrator block completes the interpolation and decompression of the data.

Abstract: An electronic musical instrument having a waveform memory of a relatively small capacity for storing waveform information similar to conventional waveform information, the waveform memory being compatible with any data reading scheme. The waveform information is stored in the form of a plurality of frames. Each frame includes a plurality of pieces of sampled waveform data compressed by ADPCM or the like and decode information for extending the sampled waveform data to be read next to the current frame. Storing the decode information in a frame for extending the sampled waveform data stored in frames before and after that frame makes it possible to extract the necessary decode information from the frame read immediately before regardless of whether the frames are read forward or backward.

Abstract: An audio signal analyzer and encoder is based on a model that considers audio signals to be composed of deterministic or sinusoidal components, transient components representing the onset of notes or other events in an audio signal, and stochastic components. Deterministic components are represented as a series of overlapping sinusoidal waveforms. To generate the deterministic components, the input signal is divided into a set of frequency bands by a multi-complementary filter bank. The frequency band signals are oversampled so as to suppress cross-band aliasing energy in each band. Each frequency band is analyzed and encoded as a set of spectral components using a windowing time frame whose length is inversely proportional to the frequency range in that band. Low frequency bands are encoded using longer time frames than higher frequency bands.

Abstract: A signal generating apparatus and a signal generating method, for storing specific sampling data D.sub.M, wherein 0<M<N-1, selected among sampling data D.sub.i obtained by sampling a wave in sampling points P.sub.i, wherein i=0, 1, 2, . . . N-1, and differential wave data .DELTA.WD.sub.n, wherein n=1, 2, 3, . . . , M-1, M+1, . . . N-2, N-1, obtained by ".DELTA.WD.sub.n =D.sub.n -D.sub.n-1 ", consecutively generating wave readout address A.sub.M for designating the specific sampling data D.sub.M and wave readout address A.sub.n for designating the differential wave data .DELTA.WD.sub.n, storing the specific sampling data D.sub.M designated by the wave readout address A.sub.M in temporary storage, when the generated wave readout address is A.sub.M, or accumulating the differential wave data .DELTA.WD.sub.n designated by the wave readout address A.sub.n in the temporary storage, thereby to generate sampling data YD.sub.n, when the generated wave readout address is A.sub.

Abstract: A musical sound generating apparatus creates a waveform to generate a musical sound according to performance information. In the apparatus, a first waveform generator is operable for creating a waveform. A second waveform generator is operable independently from the first waveform generator for creating a waveform. An input device provides performance information. A designating device designates at least one of the first waveform generator and the second waveform generator in correspondence with the provided performance information. A controller selectively operates the designated one of the first waveform generator and the second waveform generator to create the waveform according to the provided performance information. An output device generates the musical sound based on the created waveform.