A music playing system includes a number of music playback units with playback changer devices, coding units, and ISDN cards. Each of the music playback units is provided with playable pieces of music. There is at least one input unit by means of which the pieces of music to be played on a playback...http://www.google.com/patents/US5691964?utm_source=gb-gplus-sharePatent US5691964 - Music playing system with decentralized units
