Abstract: A method for frequency modulation synthesis and apparatus for performing the method. The method uses additions rather than multiplies and therefore saves the space and cost of multipliers in circuit implementations. The method saves further resources by using the coordinate rotation digital computer (CORDIC) algorithm to acquire sine values as opposed to an extensive sine look-up table. The method can be implemented with either a dedicated digital circuit or a programmed special purpose processor such as a digital signal processor. The hardware for implementing the method is normally integrated onto a semiconductor device.

Abstract: A musical sound generating system not requiring a memory unit or interpolation device for generating a tone having a tone color including a large number of harmonic components. The tone is generated with few operations and ready predictability of tone color. The musical sound generating system includes an adder for phase modulating a carrier wave by adding modulating wave data to carrier wave phase angle data; a pseudo-sinusoidal wave operator for outputting a pseudo-sinusoidal wave in response to phase-modulated carrier wave phase angle data from the adder; and a multiplier for generating a tone signal by multiplying the pseudo-sinusoidal wave by amplitude coefficient data. The pseudo-sinusoidal wave operator controls modulation of the pseudo-sinusoidal wave in accordance with a function modulation coefficient that is supplied to the operator as an external parameter.

Abstract: According to the invention, a plurality of pieces of frequency modulation information are weighted independently and then synthesized. The individual pieces of synthesized frequency modulation information are weighted independently, and individual pieces of sound data that have been generation speed controlled according to the individual pieces of frequency modulation information are synthesized. In this way, the individual pieces of frequency modulation information are weighted independently. Thus, the individual weighting processes may be changed in various ways without mutual restriction to produce for various changes in the frequency modulation.

Abstract: Variable frequency sawtooth waveforms are often utilized as an excitation signal in a digital musical synthesizer. A problem exists at lower sampling rates in such systems due to an aliasing problem which occurs at frequencies near the Nyquist rate. Low pass filtering may be utilized to mask this problem; however, low pass filtering is very time consuming to implement in a ditigal signal processor. The method and apparatus of the present invention reduces the upper harmonic content of a sawtooth waveform by proportionally converting the sawtooth waveform to a triangle waveform in response to variations in the frequency of the sawtooth waveform. This is accomplished by adding a selectable offset to the sawtooth waveform and then taking the absolute value of the resultant waveform. By restoring this waveform to a zero offset, the sawtooth waveform excitation signal will be converted to a triangle waveform having a substantially reduced upper harmonic content.

Abstract: A musical tone synthesizing device employing an operator, for generating musical tone signals by a modulation operation process. The device also employs a waveguide combined to the operator, for generating a reciprocating signal including a delay circuit for delaying the signal inputted into the waveguide feedback path, and for feeding back the output signal of the delay means to the signal, reciprocating within the waveguide.

Abstract: A musical tone parameter generating method and a musical tone generating device of this invention feature that when data inputted by a player is inputted into a neural network as input pattern, the neural network infers the parameters necessary to specify a musical tone wave form to be formed. This makes it possible to get parameters other than those stored in a memory by inferring, which increases variation of the musical tone to be generated.

Abstract: In this electronic musical instrument a musical tone is generated by frequency modulation employing a carrier wave and a modulating wave. Plural tone production channels are employed and a key assigner assigns production of a tone corresponding to a depressed key to an available channel. Tone production is achieved by a frequency modulation operation carried on in a time-shared manner for each channel. In order to achieve complex variation in harmonic content of the tone signal which is generated, the frequency of the carrier wave varies with the passage of time.