Abstract: A touch sensing circuit operable to sense a conductor approaching a sensor capacitance by measuring a response signal obtained from the sensor capacitance according to an applied detection signal includes an A/D converter and a Fourier transform device. The A/D converter samples the response signal with a predetermined cycle, followed by conversion to a digital value and outputs as time-series response data. The Fourier transform device calculates, from the time-series response data, a result of transformation at a detection frequency representing the reciprocal of a cycle of the detection signal and outputs it. The touch sensing circuit converts the response signal to the frequency domain, calculates only components (harmonics or others as needed) of a frequency equal to that of the detection signal required for touch sensing, and supplies them for a touch coordinate calculation process in a subsequent stage.

Abstract: A method for detecting an open current transformer in an electrical power system includes measuring for a voltage value on a secondary side of a current transformer. The method continues with observing the voltage value for a predetermined waveform and initiating corrective action in the electrical power system upon detection of the predetermined waveform.

Abstract: An audio signal processing method includes following steps: playing a fundamental frequency signal by a media player; calculating a first fundamental frequency sound pressure value and a first harmonic sound pressure value of the fundamental frequency signal, and calculating a second fundamental frequency sound pressure value and a second harmonic sound pressure value of the audio signal; calculating a threshold sound pressure value according to the first fundamental frequency sound pressure value, the first harmonic sound pressure value, and the second fundamental frequency sound pressure value; and comparing the second harmonic sound pressure value and the threshold sound pressure value to generate a comparing result, and adjusting the second harmonic sound pressure value according to the comparing result. An audio signal processing device is also disclosed.

Abstract: A method includes receiving an audio signal and identifying one or more steady-state segments of the audio signal. The method also includes identifying at least one portion of the one or more segments that contains a specified frequency. Further, the method includes generating a wavetable using the at least one identified portion of the one or more segments. In addition, the method could include synthesizing an output audio signal using the wavetable. The output audio signal could represent a ringtone in a mobile telephone.

Abstract: Methods and apparatus for relative pitch tracking of multiple arbitrary sounds. A probabilistic method for pitch tracking may be implemented as or in a pitch tracking module. A constant-Q transform of an input signal may be decomposed to estimate one or more kernel distributions and one or more impulse distributions. Each kernel distribution represents a spectrum of a particular source, and each impulse distribution represents a relative pitch track for a particular source. The decomposition of the constant-Q transform may be performed according to shift-invariant probabilistic latent component analysis, and may include applying an expectation maximization algorithm to estimate the kernel distributions and the impulse distributions. When decomposing, a prior, e.g. a sliding-Gaussian Dirichlet prior or an entropic prior, and/or a temporal continuity constraint may be imposed on each impulse distribution.

Abstract: A pickup processing system for a guitar or other musical instrument. According to one embodiment, a split pickup is employed that separates the sound from the two bass strings from the other four strings. The signal from the bass strings may be provided to an octave divider, which creates a bass sound to add back into the sound. The octave divider produces sound without discontinuities or other artifacts. Other effects include restored acoustical properties of the guitar body, stereo imaging, reverb and others. The present invention may be fully contained within the body of an acoustic guitar.

Abstract: A signal processing apparatus is disclosed which processes an audio signal. The signal processing apparatus includes a detection section which detects a first tempo from an audio signal, a calculation section which calculates a speed feeling that indicates whether the first tempo is fast or slow, and a determining section which determines a second tempo by correcting the first tempo using the speed feeling.

Abstract: An audio looping method and system that stores a segment of an audio signal and plays back the stored segment in a repeated loop. The beginning and the end of the audio segment are determined by changes in the audio signal, instead of a predetermined time interval or a time specified by manual user input. This produces a repeated loop that is timed to an event in the audio signal.

Abstract: Tone quality is improved at the time of playing back sound data having a loop part. A sound data encoding apparatus encodes sound data in groups of a plurality of consecutive blocks. In the case where the sound start position is equal to the loop start position, encoding is performed using samples of sound data (for example, sound data just before the loop end) relating to the sound data at the sound start position from the viewpoint of music. In the case where the sound end position is equal to the loop end position, encoding is performed using samples of sound data (for example, sound data just after the loop start) relating to the sound data at the sound end position from the viewpoint of music.

Abstract: There is provided a method of synthesizing a musical instrument digital interface (MIDI) having wave table support. The wave table sample information is modified based on the newly searched loop segment, the interval of the newly searched loop segment, and the fine tune data. Therefore, the size of the wave table can be reduced.

Abstract: To store main information with associated additional information incorporated therein, data constituting the additional information is divided into a plurality of small-size data pieces of, e.g., one bit. Then, the respective values of particular ones of predetermined data units (e.g., bytes) constituting the main information are subjected to arithmetic operations in accordance with a predetermined algorithm containing the value of each of the data pieces as a parameter. In this way, the respective values of the particular data units in the main information are modulated in accordance with the values of the individual data pieces in the additional information; at that time, only some of the data unit values are altered with the others left unaltered. The thus-arithmetically-operated main information is stored into a storage.

Abstract: Filtering is performed on original waveform to remove components of a predetermined frequency band from the waveform, and dividing positions of the original waveform data are determined on the basis of envelope levels of the filtered waveform. The dividing positions may be determined on the basis of differentiation of an envelope of the filtered waveform. Rise positions in the original waveform data are detected, and one rise position may be selected from among one or more rise positions detected within a predetermined range of the original waveform and extracted as a dividing position of the original waveform. Presumed beat positions in the original waveform may be detected, and rise positions of the original waveform may be detected within predetermined ranges corresponding to the presumed beat positions.

Abstract: A storage-medium rental system includes a portable storage medium to be rented to the user, a portable semiconductor memory owned by the user, a rental-shop apparatus owned by the rental agent, and a reproduction apparatus owned by the user. The storage medium prestores encrypted content which is generated by encrypting digital work by using a content encryption key. The semiconductor memory has an area for securely storing a content decryption key. The rental-shop apparatus stores a content decryption key for decrypting the encrypted content. The rental-shop apparatus writes the content decryption key to the semiconductor memory. The reproduction apparatus securely reads the content decryption key from the semiconductor memory, reads the encrypted content from the storage medium, decrypts the encrypted content by using the content decryption key, and reproduces the decrypted content.

Abstract: A touch curve memory 110 stores therein a touch curve formed by velocity values corresponding to touch data generated by a keyboard device 20. A correction coefficient generator 10 generates a correction coefficient composed of a ratio of one of the velocity values stored in the touch curve memory corresponding to one of the touch data generated by the keyboard device, in a maximum touch memory mode switched by a mode switch 21 (SW1), to a maximum value of the velocity values in the touch curve memory. A corrector 10 multiplies the correction coefficient generated by the correction coefficient generator by the respective velocity values stored in the touch curve memory, and then generates a touch curve formed by new velocity values. Accordingly, it is possible to provide a touch control apparatus and a touch control method which can obtain a touch curve, from which a touch response suitable for a user can be obtained, easily and in a short time.

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: There are provided a power line spectrum extractor for extracting power line spectra of a waveform to be processed; a level interpolation controller for performing level interpolation control on the power line spectra at every unit of a certain frequency, which is not higher than half a sampling frequency; and a cepstrum analyzer for performing Fast Fourier Transformation on the power spectra subjected to the level interpolation control and performing Inverse Fast Fourier Transformation on values found by performing level setting with a specified coefficient.

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: A musical scale recognition apparatus includes an analog/digital converter and a processor, and can determine by the processor how close an input analog audio signal is to a musical scale of a musical tone to be recognized by repeatedly performing a calculation of a cumulative value As to find a coefficient of a Fourier sine series of the audio signal on the basis of a frequency f and digital data D, a cumulative value Ac to find a coefficient of a Fourier cosine series of the audio signal on the basis of the frequency f and the digital data D, and a frequency power spectrum effective value A of the audio signal on the basis of the cumulative value As and the cumulative value Ac, wherein the digital data into which the input analog audio signal is converted by the analog/digital converter is D, the frequency (musical scale) of the musical tone to be recognized is f, and a current time is t.

Abstract: There are provided a power line spectrum extractor for extracting power line spectra of a waveform to be processed; a level interpolation controller for performing level interpolation control on the power line spectra at every unit of a certain frequency, which is not higher than half a sampling frequency; and a cepstrum analyzer for performing Fast Fourier Transformation on the power spectra subjected to the level interpolation control and performing Inverse Fast Fourier Transformation on values found by performing level setting with a specified coefficient.

Abstract: A musical sound signal synthesizer with a simple construction for synthesizing complex musical sound waveform signals including many harmonics in a peculiar form. A phase information generator 11 supplies phase information x with a sawtooth wave changing according to a phase of the musical sound to be generated via a calculator 12 to a sine wave table 13, from which output waveform information y is read out. The waveform information y is fed back to the calculator 12 via an absolute value transformer 14, a low pass filter 15 and a gain controller 16. The output waveform information y outputted from the sine table 13 is transformed nonlinearly, which is fed back to the phase information x, which makes a complex change. As a result thereof, the waveform, which is represented by waveform information outputted from the sine wave table 13, becomes peculiar for a musical sound signal synthesized by phase or frequency modulation technique.

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: In accordance with the present invention, a method and apparatus are provided wherein loop discontinuities are eliminated. In the case of amplitude discontinuities, the harmonic amplitudes contained in the loop are progressively scaled over the duration of the loop, so that for each harmonic the loop end amplitude matches the loop beginning amplitude. In the case of phase discontinuities, the harmonic phases are progressively shifted over the duration of the loop, so that for each harmonic the loop end phase matches the loop beginning phase. Shifting the phase is accomplished by slightly altering the frequency of the harmonics to produce the desired amount of phase-shift at the loop end. In accordance with the present invention, the method also provides a technique to select loop begin and end points to minimize the amount of phase adjustment.

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 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: In accordance with the present invention, a method and apparatus are provided wherein loop discontinuities are eliminated. In the case of amplitude discontinuities, the harmonic amplitudes contained in the loop are progressively scaled over the duration of the loop, so that for each harmonic the loop end amplitude matches the loop beginning amplitude. In the case of phase discontinuities, the harmonic phases are progressively shifted over the duration of the loop, so that for each harmonic the loop end phase matches the loop beginning phase. Shifting the phase is accomplished by slightly altering the frequency of the harmonics to produce the desired amount of phase-shift at the loop end. In accordance with the present invention, the method also provides a technique to select loop begin and end points to minimize the amount of phase adjustment.

Abstract: Basic tone waveform corresponding to a designated tone color and pitch is generated in each of a plurality of channels. Effect is imparted to the basic tone waveform in accordance with an algorithm for providing a predetermined effect, independently for each of the channels. The effect to be imparted is controlled in accordance with the designated tone pitch, separately for each of the channels. The effect impartment may be conducted using a processor, such as a DSP, executing a predetermined program containing a predetermined effect-imparting algorithm. In one example of the effect-imparting algorithm, a delay loop is employed through which an input exciting signal is circulated while being delayed, and an effect specific to an electromagnetic pickup of an electric guitar can be approximated by controlling the delay amount in the delay loop.

Abstract: A pitch/tempo converting apparatus is constructed for concurrently changing a tempo and a pitch of an audio signal according to tempo designation information and pitch designation information. In the apparatus, a memory section memorizes the audio signal composed of original amplitude values sequentially sampled at original sampling points timed by an original sampling rate within an original frame period. A tempo converting section converts the original frame period into an actual frame period by varying a length of the original frame period according to the tempo designation information so as to change the tempo of the audio signal. A pitch converting section converts each of the original sampling points into each of actual sampling points by shifting each of the original sampling points according to the pitch designation information so as to change the pitch of the audio signal.

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: A musical tone generation apparatus creates musical-tone-waveform samples based on waveform samples stored in a waveform memory by each sampling period. Herein, a high-speed bus such as a PCI bus is provided for data transfer with regard to the waveform memory. A waveform buffer is provided to temporarily and selectively store the waveform samples which are read from the waveform memory. A sound source operates in accordance with time-division-channel timings which are provided by dividing a sampling period by a number of channels. The sound source performs interpolation calculations on the waveform samples of the waveform buffer to create a musical-tone-waveform sample in accordance with each time-division-channel timing with respect to each channel. The apparatus generates a read address whose value is changed in response to a pitch of a musical tone.

Abstract: An improved method for shifting the pitches of a tone is disclosed. It comprises: (a) subjecting a digitized original waveform to a whitening process using an all-zero filter (AZF) to obtain a whitened waveform; (b) resampling the whitened waveform at a desired scaling ratio to obtain a scaled and whitened waveform; (c) subjecting the scaled and whitened waveform to a coloring process using an all-pole filter (APF) to obtain a synthesized waveform. In a preferred embodiment, the all-zero filter performs the transformation function of: ##EQU1## and the all-pole filter performs the transformation function of: ##EQU2## wherein the a.sub.i 's and b.sub.i 's are linear predictive coefficients. The whitened waveforms can be compressed and stored as wavetables, which can be subsequently retrieved and decompressed before resampling.

Abstract: A musical tone-generating method and apparatus therefor are provided. Musical tones are generated by reading waveform data from a waveform table at a predetermined sampling frequency and carrying out arithmetic operations on the waveform data read from the waveform table to generate musical tone waveform samples, by the use of a processing unit. A first sampling frequency or a second sampling frequency lower than the first sampling frequency is selected as the predetermined sampling frequency. Interpolation of the waveform data read from the waveform table is effected by a second interpolation method which is lower in accuracy than a first interpolation method employed when the first sampling frequency is used, or alternatively the interpolation is inhibited, when the second sampling frequency is selected as the predetermined sampling frequency.

Abstract: The number of waveform samples per unit time, i.e., waveform sample forming resolution is variably set depending on characteristics of a tone to be generated, such as construction of harmonic components in the tone. The number of waveform samples per unit time is increased for a tone or portion (e.g., attack portion) of a tone containing a relatively great number high-order harmonic components. Conversely, for a tone or portion (e.g., sustain portion) of a tone containing fewer high-order harmonic components, the number of waveform samples per unit time is decreased. By thus variably setting the waveform sample resolution, a process for arithmetically forming waveform sample data can be performed efficiently without involving significant waste. In cases where a plurality of tone generating channels are provided, the waveform sample forming resolution may be variably set independently for each of the channels.

Abstract: Waveform memory (12) stores a plurality of consecutive waveform sampling value data at a single address. Even when some waveform sampling values are skipped in a process of reproducing a musical tone of a frequency higher than a pitch inherent to a waveform prestored in the memory (12), all of the consecutive sampling values are sequentially read out and stored in temporary storage means (40.about.46) so that the interpolation calculation is accurately performed using the consecutive sampling values.

Abstract: A method of building a database of timbre samples for music synthesizers is provided, which can help provide smooth transitions between adjacent looping waveforms in the looping segment of the synthesized sound waveform, and also help provide an optimal tradeoff between high timbre quality and low timbre vibrations. The method utilizes a cosine looping-waveform transformation function to obtain an optimized looping waveform that can be repetitively appended to the timbre sample with smooth transitions between adjacent looping waveforms such that the resultant synthesized sound waveform is free from ripples that will otherwise affect the reproduced timbre quality of the synthesized sound. Moreover, the method utilizes a timbre-balancing function that can help provide an optimal tradeoff between high timbre quality and low timbre vibrations. The reproduced timbre quality of the synthesized sound from the wave-table music synthesizer is thus very high.

Abstract: A data sample series access system including an interpolating section for obtaining, by interpolation, sound data at a timing indicated by a sound interpolation timing signal by using at least two adjacent sound data signals, and a selecting section for outputting the sample of sound data as a sound output signal at a timing indicated by a sound output timing signal. The data sample series access system avoids problems caused by a delay in memory access operations of the sound data.

Abstract: An electric guitar amplifier which utilizes a digital signal processor to produce vacuum-tube-like distortion without certain unwanted audio artifacts created by previous digital realizations of nonlinear, high-gain functions. By virtue of a microprocessor-controlled digital signal processor embodiment, the invention gives the user programmable control over parameters normally associated with state of the art guitar amplifiers (e.g. tone controls, reverb controls, tremolo controls, etc.), as well as other musically useful parameters which are not normally included among the controls of a guitar amplifier (e.g. selection of preamp type, autovolume, reverberation type, autowah, etc.).

Abstract: A pedal controller monitors a damper pedal incorporated in an acoustic piano, and reduces the amount of music data information represented by digital pedal position signals through an anti-aliasing filtering, a decimation and an interpolation without sacrificing the accuracy of the pieces of music data information.

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. The present invention includes a plurality of interpolator circuits utilizing a single waveform memory where each of the interpolator circuits produces a unique bus request signal which is responsive to a unique bus acknowledge signal to determine which of the interpolator circuits has control of the waveform memory at any given waveform memory cycle.

Abstract: A method, for forming a repeated waveform that is employed for an electronic musical instrument, which includes the steps of: setting, as basic data, a loop top address, an initial value of a loop length, and a length change range; changing the loop length within the length change width; forming repeated waveforms that are obtained after cross-fading is performed in consonance with existing conditions; acquiring correlation coefficients of the repeated waveforms, which are obtained by cross-fading, and waveforms at corresponding portions of an original waveform; and selecting a predetermined number of waveforms beginning at a waveform that is most correlative to determine a repeated waveform, and an apparatus therefor.

Abstract: A pitch-asynchronous-type musical tone creating apparatus, provided for an electronic musical instrument, comprises at least a waveform memory, a low-pass filter and an interpolation section. Waveform samples, stored by the waveform memory, are sequentially read out, so that the interpolation section performs interpolation process on the waveform samples to create interpolation samples. Musical-tone parameters, such as a tone-color characteristic and an envelope characteristic, are imparted to the interpolation samples so as to create musical-tone samples. When performing reading operations on the waveform memory at a high speed which causes skipping of the reading operations, certain frequency components, which cause occurrence of folding noises, are incorporated into the interpolation samples. Those frequency components are removed from the waveform samples, read from the waveform memory, by the low-pass filter whose cut-off frequency is determined responsive to a frequency number.

Abstract: A musical sound generating device has a waveform memory to store musical sound waveform data to be read-out repeatedly between a loop-top address (integral address) and a loop-end address (integral address). The same musical sound waveform data is stored at the loop-top address and the loop-end address. An address computing circuit computes a read-out address, including a decimal part, to repeatedly read out the musical sound waveform data stored between the loop-top address and the loop-end address in the waveform memory. An interpolating circuit carries out interpolation if the read-out address generated by the address computing circuit includes a decimal part. Interpolation is carried out by dividing in proportion the musical sound waveform data read out from the waveform memory using an integral part of the read-out address and the musical sound waveform data read out from the waveform memory using a value obtained by adding 1 to the integral part of the read-out address according to the decimal part.

Abstract: An electronic musical instrument produces musical tones based on waveform data, while providing smooth changes between different timbres and at the same time avoiding reduction in the efficiency of waveform compression. The timbre change is carried out in an interpolation interval, the magnitude of which varies in accordance with the magnitude of the timbre change. The data necessary to establish the interpolation interval may be stored and read out of a memory or may be determined by interpolation according to a linear function.

Abstract: A tone generator for an electronic musical instrument analyzes an original waveform signal to store results of analysis thereof into a memory. The results of the analysis read out from the memory is interpolated to generate results of the interpolation in synchronism with each sampling clock. The results of the analysis are corrected to cancel a frequency characteristic to be imparted to the results of the analysis when they are interpolated. The results of the analysis are stored into the memory after having been converted. In another form, a reading numerical value formed of an integer part and a decimal part is generated, in synchronism with a predetermined clock timing. The numerical value is variable at a rate proportional to the pitch of a musical tone to be produced. Residual waveform samples read from the memory based on the integer part are interpolated by the use of the decimal part in synchronism with a predetermined clock timing.

Abstract: A technique for digitally processing a counterpart of a musical sound first transforms a set of time-domain samples of the sound into frequency-domain counterparts, gradually coerces the frequency-domain counterparts into integer multiples of a fundamental frequency of the sound, and then, in each of a plurality of amplitude transition portions, gradually changes the amplitudes of the frequency-domain counterparts from the beginning to the end of each amplitude transition portion.

Abstract: A memory stores waveform sample data for plural sample points forming a given tone waveform, and one of the stored waveform sample data stored for every two adjacent sample points is expressed in PCM representation while the other is in difference value representation that is based on the PCM values stored for two sample points on both sides of the sample point of the other sample data. The number of bits in each address of the memory is greater than the number of bits in each of the PCM data, and each of the PCM data is stored at some bit positions of one address, while the difference value data is stored at the remaining bit positions of one or more addresses.

Abstract: Reading of a waveform memory is controlled and one of different processing is performed depending upon which of a first mode and a second mode has been designated. When the first mode has been designated, an interpolation operation is performed on the basis of plural sample value data read from the waveform memory by using a predetermined number of processing time slots and a resulting one waveform sample value data is produced. When the second mode, has been designated, a processing for producing one waveform sample value data is performed on the basis of one sample value data read from the waveform memory by using one processing time slot. By using a predetermined plural number of processing time slots, one waveform sample value data produced with a high accuracy in the first mode whereas plural waveform sample value data are produced in the second mode whereby generation of a waveform can be performed efficiently by properly utilizing the mode.

Abstract: A musical tone control waveform signal generating apparatus is provided in order to generate a musical tone control waveform signal by which a musical tone generated from an electronic musical instrument is to be controlled. The musical tone control waveform signal is varied in its envelop level by each of time-division sections to be passed over a lapse of time. For instance, when a key-depression event is occurred, this musical tone control waveform signal of each time-division section is formed by carrying out a computation by use of parameters which are preset with respect to each section. Preferably, the parameters concern with the variation rate and target level of the musical tone control waveform signal to be formed by each section.

Abstract: A waveform-forming device has a waveform memory storing a plurality of blocks of waveform samples representative of a waveform of a musical tone. Each block is formed of at least one non-compressed waveform sample and a plurality of compressed waveform samples. A pitch of a musical tone to formed is taken in. The waveform samples are read out block by block from the waveform memory, based on the pitch taken in. The compressed waveform samples contained in each block are converted into non-compressed waveform samples. The waveform of the musical tone is formed from the at least one non-compressed waveform sample of each block and the non-compressed waveform samples obtained by the conversion.

Abstract: Tone waveform data is divided into plural data segments, so that frequency and magnitude of respective spectra contained therein are analyzed for each of the data segments. Analyzation parameters indicative of the frequency and magnitude of the respective spectra for each said data segment which has been obtained through the analyzation is stored into a memory. The analyzation parameter for each data segment is sequentially read out from the memory, and the tone waveform data is reanalyzed on the basis of the read-out parameter. To control the frequency of a resulting tone, a data shift circuit may be provided which serves to shift the value of the frequency data contained in the analyzation parameters.

Abstract: An electronic musical instrument, which is configured to simulate one or more instruments, provides a sound source, a display unit and a control portion. Herein, under control of the control portion, the display unit displays the predetermined graphic pattern corresponding to the tone-generation mechanism, i.e., tone-generation algorithm of an instrument to be simulated. The sound source contains a drive portion, a tone-generation portion and a resonance-radiation portion, each of which further contains a digital signal processor (DSP). All of these portions function to create a digitized musical tone signal corresponding to a simulated sound of the instrument by combining operation data outputted from the DSPs. By controlling the display unit, it is possible to arbitrarily vary the contents of the displayed tone-generation algorithm, so that the performer can easily and freely perform a music on this electronic musical instrument.