Method and apparatus for reproducing a musical presentation

Abstract From the Canadian patent

There is disclosed n method and apparatus for reproducing a musical presentation wherein musical data from, such presentation. such as keyboard situations of a keyboardtype musical instrument, is encoded and stored in a code which has information contained in the translations only and the sense and direction of such transitions are ignored. This avoids several major drawbacks of bi-phase level code previously disclosed because the (1) phase of the signal need not be maintained, and (2) the bi-phase level code cannot be recovered following a dropout until a 1-0 or a 0-1 transition occurs. There is also disclosed n data dropout detection system for assuring that the wrong music is not played.