Abstract: An operating member control device of an electronic musical instrument is constructed by a main unit and a plurality of subunits, each of which has a operating member for setting a musical tone element and a drive mechanism for moving the operating member. The main unit transmits in serial form a set of control data signals, which are preset in advance, designating desired target positions of the operating members respectively. The subunits further include serial to parallel converters, each of which receives the control data signals and serial-to-parallel converts the corresponding one of the control data signals. The operating members are moved from the current positions to the desired positions designated by the parallel converted control data signals respectively. By the construction as above, this operating member control device need a single line only with respect to the connection of the main unit and the subunits basically, thereby enabling simple wiring.

Abstract: A musical tone is synthesized by frequency modulation which realizes a desired fixed formant. A first accumulator repeatedly adds a constant corresponding to a center frequency of the fixed formant at a regular time interval to generate phase angle data of a carrier. A second accumulator repeatedly adds a constant corresponding to a fundamental frequency of a selected note at a regular time interval to output a carry out signal each time the accumulated value has exceeded a predetermined modulo number. By resetting the first accumulator repeatedly by this carry out signal, the phase angle data of the carrier is brought into a harmonic relation with the fundamental frequency. By effecting frequency modulation using this phase angle data of the carrier and the fundamental or harmonic frequency of a selected note, a musical tone in which harmonic components of the selected note are controlled in accordance with the desired fixed formant is synthesized.

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: 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: There are provided means for generating a digital information which varies periodically and repeatedly at a rate corresponding to the pitch of a tone to be produced, a plurality of function generators respectively supplied with the digital information for producing different linear functions, means for selecting the outputs of the function generators at a timing related to the period of the digital information and means responsive to the selected output of a function generator for generating a musical tone.

Abstract: An electronic musical instrument is of a waveshape memory read out type which includes a waveshape memory device for storing amplitude values at respective sampling points in one period of a new musical tone waveshape to be generated subsequent to a present musical tone waveshape stored in another waveshape memory device, first calculating means for calculating differences in amplitude values at respective sampling points stored in corresponding addresses of the two waveshape memory devices respectively; renewal rate control means for generating a waveshape renewal signal having a period corresponding to difference information produced by the first calculating means, and renewal means for effecting renewal of the memory content of said another waveshape memory device at a rate corresponding to the period of the waveshape renewal signal.

Abstract: There are provided a plurality of key switches which respectively designate the pitches of the musical tones to be generated, a frequency number generator which generates frequency numbers corresponding to the respective key switches, a harmonic order number generator which generates harmonic order numbers representing the orders of the respective harmonic components, an arithmetic processor for producing a multiplication product of the frequency number and the harmonic order number, an accumulator which repeatedly accumulates the output of the arithmetic processor of each harmonic order at a predetermined speed, and a sinusoid table including a memory device storing the amplitude values at respective sampling points of a sinusoidal wave for generating the amplitude values of the sinusoidal wave corresponding to respective harmonic components thereby producing the harmonic components.

Abstract: There is provided a first waveform generator which repeatedly generates a first waveform having a relatively short period in response to a first constant parameter, a second waveform generator responsive to a second constant parameter for generating a second waveform having a longer period than the repeatedly generated waveform and gradually approaches to zero in the later half of its period, a multiplier for multiplying the first waveform and the second waveform to form a musical tone waveform element, and means for resetting the waveform generating operations of the first and second waveform generator at a period corresponding to the tone pitch of a depressed key. Sequential alignment of the musical tone waveform elements constitutes a musical tone waveform having a tone frequency determined by the resetting period. The changes in the parameters cause changes in the tone color.

Abstract: In an electronic musical instrument wherein waveshape F(x, y) is computed and the resultant waveshape is converted to a musical tone, computation of said waveshape F(x, y) is carried out in accordance with either one of the following equations: ##EQU1## WHEREIN: F(X), F(Y) REPRESENT MATHEMATICAL FUNCTIONS OF TIME, RESPECTIVELY; AND N REPRESENTS AN ARBITRARY INTEGER.

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

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

Abstract: An electronic musical instrument capable of changing a slope portion of a filter characteristic continuously from start to completion of production of a musical tone.The inventive electronic musical instrument changes a filter slope in a frequency region above or below a cut-off frequency with lapse of time and, in order to achieve such change in the filter slope, changes a slope factor continuously from start to completion of production of the tone. The instrument is also capable of changing the cut-off frequency.An example of a low-pass filter is shown in which a desired form of a successively changing filter slope can be obtained by employing four slope factor values and three values representing a speed of change of the slope factors as well as three cut-off frequency values and two values representing a speed of change of the cut-off frequencies.

Abstract: An electronic musical instrument wherein instantaneous amplitude values of respective harmonics of a musical tone waveform are individually provided in accordance with a numerical value corresponding to the frequency of the depressed key for the musical tone, each of harmonic amplitude coefficients setting relative amplitudes of the respective harmonics is multiplied with corresponding one of the instantaneous amplitude values and the multiplication products are aligned with respect to time thereby to obtain a musical tone of a desired tone color, i.e. of a desired frequency spectrum construction. The harmonic amplitude coefficients are given as values corresponding to a multipeak spectrum construction.The harmonic amplitude coefficients are provided by a filter having a multipeak characteristic.

Abstract: In an electronic musical instrument of the class wherein the amplitude samples of a tone at successive sampling points of musical tone waveform are calculated by independently calculating respective partials that constitute the musical tone waveform and then adding the calculated partial samples, there are provided a "variable" generating circuit which generates a variable which varies with time, and a "variable" modifying circuit which modifies the variable with a coefficient corresponding to each partial thereby independently modifying the normal frequency of each one of the correponding partials in accordance with the output from the variable modulating circuit.

Abstract: The electronic musical instrument according to the invention is capable of controlling each level of harmonics constituting a musical tone individually and independently from each other and thereby producing a musical tone which is a close simulation of a natural musical tone. In order to produce change in the level of each harmonic with the lapse of time separately and independently, information respectively representing a peak level of attack, attack time from start of generation of a tone to the peak level, a sustain level and decay time from the peak level to the start of the sustain level is memorized for each harmonic and the level of each harmonic is controlled in response to such information.In one example of the electronic musical instrument, the level of each harmonic constituting a musical tone is amplitude-modulated with a different period and depth.

Abstract: An electronic muscial instrument capable of calculating level information of slope portion of a filter characteristic on the basis of the inclination of the slope and the cut-off frequency without requirement of storing level information of the slope portion for each individual frequency.The inventive electronic musical instrument is also capable of obtaining level information of an acute portion of filter characteristic which constitutes selectivity Q by calculating the inclination and peak value of the acute portion and difference between the peak frequency and the cut-off frequency.An example is shown in which the cut-off frequency is caused to successively change during a period of time from the start to the end of playing of a musical tone and in which the peak of the selectivity Q can be directed either upward or downward as desired.

Abstract: An electronic musical instrument capable of producing a multi-system tone source effect which is an effect providing a musical tone with naturalness and resulting from simultaneous playing of a tone of a proper pitch and a tone of a pitch slightly different from the proper pitch. The inventive electronic musical instrument produces this effect with a smaller number of tone source devices than the number of systems.Composite musical tone waveshape amplitudes achieving the multi-system tone source effect can be represented by a single multiplication term of a sine waveshape function content corresponding to a certain pitch and a cosine waveshape function content corresponding to a pitch difference. According to the invention, the sine waveshape function content and the cosine waveshape function content are separately produced and these contents are multiplied with each other to produce the composite musical tone waveshape amplitudes.

Abstract: An electronic musical instrument capable of producing a large number of harmonic contents with a small number of calculation circuits. A composite wave consisting of plural harmonics can be mathematically expressed as a multiplication of a factor including an order number of a harmonic and a factor or factors not including an order number of a harmonic. The instrument according to the invention utilizes this principle and produces a composite wave by first obtaining these two kinds of factors individually and thereafter multiplying them together.An example of the invention capable of calculating four harmonics simultaneously and another example capable of calculating two harmonics simultaneously are described.

Abstract: An electronic musical instrument capable of producing any desired combination of two tones of mutually different footage. According to the invention, such combination of tones can be produced from only two tone sources without providing tone sources of an equal number to a total number of footage to be coupled. In view of the fact that musical tone waveshape amplitudes of two coupled tones of different footage can be represented by a multiplication term of a sine wave content and a cosine wave content, these two waveshape contents are individually calculated and then combined to form amplitudes of a composite musical tone waveshape.

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