A first control may be for setting a tempo upon which a performance position, which may be set with a second control, may be based. Circuitry may be selectively passing inputted musical tone signal. A processor may be configured for processing data for controlling an output signal of the circuitry based...http://www.google.fr/patents/US8058545?utm_source=gb-gplus-shareBrevet US8058545 - Effect device systems and methods
