Electronic musical instrument employing tone generator selection based on integrated residual envelope volume

摘要

An electronic musical instrument allots musical tone-generating channels to new musical tones by calculating an integrated residual generated volume or a substitute values corresponding thereto for each current musical tones; and determining which of musical tone-generating channels has a minimum such volume or substitute value. The instrument may, alternatively, allot a tone generating channel for a new musical tone by detecting a minimum envelope level of those already allotted musical tones; selecting those channels having envelope levels falling within a determined range defined based on and including the detected minimum level; and determining which channel selected by the selecting means has a minimum residual generated volumes or substitute values corresponding thereto. The residual generated volumes are determined by an equation: wherein V(t) is an envelope level at an instant "t" during a period from the given instant "to" and to the end point "tend" of the musical tone. The substitute values are given by a further equation; WL=LEVo*LEVo/(-RTo) wherein LEVo is the envelope level at the given instant, and RTo is a rate of change of the attenuating envelope level.