A waveshape memory stores waveshape data representing plural waveshapes each having plural periods. A reading sequence controller designates ones to be read out among said waveshape data from the waveshape memory and the readout order thereof. This order may either be a random order or a predetermined...http://www.google.de/patents/US4785702?utm_source=gb-gplus-sharePatent US4785702 - Tone signal generation device
