A karaoke apparatus mixes a live singing sound with a harmony chorus sound and an orchestral accompaniment sound. A first input terminal is connectable to a microphone to receive therefrom a first vocal signal representative of a first live singing sound. A second input terminal is connectable...http://www.google.es/patents/US5773744?utm_source=gb-gplus-sharePatente US5773744 - Karaoke apparatus switching vocal part and harmony part in duet play
Karaoke apparatus switching vocal part and harmony part in duet play
