Abstract: The practice of this invention enables a musician to augment a main "lead voice" performance by extemporaneously deriving from particularly selected notes of the main performance a separate synthesized accompaniment in which particularly selected notes may be controllably time-extended (e.g. sustained) singly or in a group, in effect "detached" from the lead voice. The first of a pair of low profile footswitches enables/cancels accompaniment triggering; the second enables/cancels accompaniment time-extension. Switch logic is implemented such that the first switch can never override the second switch to cancel time-extension; thus a musician operating the switches interactively, typically one with each foot, is enabled, through strategic timing relative to the lead notes, to trigger accompaniment notes from particularly selected lead notes, to controllably time-extend particularly selected accompaniment notes, and to accumulate groups of such time-extended accompaniment notes.

Abstract: Truncate processing is performed so that a new tone is not generated before the envelope waveform is finished but the new tone is produced after the volume of the previous tone is sufficiently diminished, by which the new tone can be produced with a satisfactory feeling of attack. Further, the envelope waveform is not abruptly interrupted and cleared in a moment but is decayed at a constant and high speed, thereby preventing the generation of noise such as a click. Moreover, demanded speed data is provided for each tone, by which it is possible to produce repective tones not at a demanded speed like the least common multiple but at an optimum speed for each tone and to make the previous tone generation proceed to the next tone generation without producing noise such as a click.

Abstract: At least two sets of filter coefficients corresponding to different filter characteristics are interpolated by using a control signal for controlling tone color as a parameter of interpolation. Filter coefficients obtained by the interpolation are supplied to a digital filter to determine its filter characteristics and an input tone signal is modified in accordance with the filter characteristics thus determined. Filter characteristics of diverse variation as compared with the number of prepared filter coefficients can thereby be realized. Further, timewise change of filter characteristics can be realized by changing a parameter of interpolation with lapse of time or changing two sets of filter coefficients to be interpolated with lapse of time. Designation of filter coefficients can be made by designating coordinate data of coordinates having at least two axes.

Abstract: A control waveform generating apparatus for an electronic musical instrument generates a control waveform having at least a rising portion and a falling portion whose levels vary in a lapse of time. The control waveform is divided into a plurality of segment waveforms each of which includes a constant level portion (an interval portion) and at least one of the rising portion and the falling portion therein. The rising rates and falling rates and interval durations of the respective segment waveforms are selected by a player so that the control waveform having an arbitrary waveform can be obtained. When generating the control waveform, each of the plural segment waveforms is sequentially designated and outputted as a part of the entire control waveform. When the present segment waveform next to the preceding segment waveform is designated, the last level of the preceding segment waveform is maintained in a selected interval period.