In addition to a general transposition setting device for setting a transposition for an entire musical instrument, there is provide an automatic-performance transposition setting device for optionally setting a transposition value for automatic performance. Automatic performance data is transposed in...http://www.google.co.uk/patents/US6417438?utm_source=gb-gplus-sharePatent US6417438 - Apparatus for and method of providing a performance guide display to assist in a manual performance of an electronic musical apparatus in a selected musical key
