A hybrid keyboard musical instrument includes two electric tone generators, music strings selectively struck with hammers driven for rotation by action mechanisms and a silent system for changing a hammer stopper between a free position and a blocking position, and a controlling system supplies instructions...http://www.google.com/patents/US6362405?utm_source=gb-gplus-sharePatent US6362405 - Hybrid musical instrument equipped with status register for quickly changing sound source and parameters for electronic tones
