Respecting plural accompaniment patterns belonging to a common accompaniment style, an order is predetermined in which accompaniment patterns are sequentially changed. For example, this order may be predetermined to be an order in which a change of the accompaniment patterns can accomplish a more natural...http://www.google.com/patents/US5241128?utm_source=gb-gplus-sharePatent US5241128 - Automatic accompaniment playing device for use in an electronic musical instrument
