Abstract: An electronic musical instrument having a plurality of operators for generating audio frequency waveforms and performing frequency modulation thereof. The operator comprises a wave generator, a phase generator, and an amplitude-envelope generator. The phase generator produces phase-angle data on the basis of frequency-number data modulated by ratio-of-frequency data. While the frequency-number data is common to all operators, ratio-of-frequency data varies independently of those applied to the other operators. This enables operators to create rich, dynamic, lifelike sound. One or more operators are provided with feedback loops that are capable of varying the amount of the feedback in response to key touch, etc., thus achieving expressive tone. A pitch-envelope generator is provided with a random-number generator which modulates the pitch envelope in a random manner to more closely simulate a performance on a real musical instrument.

Abstract: An automatic musical performance apparatus comprising two groups of tracks: one for storing pattern data of musical performance, the other for storing level data that modify the volume of tones produced on the basis of the pattern data, so that tone volume of each track can be altered while listening to the tone being reproduced. Tone volume varies depending on volume control and key-velocity. One of these can be selected to be modified by the level data, thus causing different effect on tone volume control. There are three kinds of level data: track, group, and total. Track level data modify each track data in the pattern data, each set of group level data modifies track data belonging to the same group, and the total level data uniformly modifies all track data. Using group level data facilitates the setting of level data. The pattern data can include a number track data having different loop length and rhythm style, thus enabling the automatic performance of polyrhythm style.