A musical tone control apparatus having first and second detectors mounted on a player's arm for detecting bending angles of the player's joints, and a musical tone control data generating circuit worn on the player's waist for generating musical tone control data based on output signals of the first...http://www.google.de/patents/US4905560?utm_source=gb-gplus-sharePatent US4905560 - Musical tone control apparatus mounted on a performer's body
