Abstract: A recording and playback system for keyboard musical instruments in which data characterizing the operation of a keyboard of the instrument is recorded in solid-state memory in the form of words specifying keys to which changes of state have taken place together with data words specifying the time intervals between such changes, both types of data words being recorded in a continuous sequence of addresses in memory and the timing signals being distinguishable from the change-of-state signals by the use of pre-arranged codes, different for each type, within the range of codes available for use as data codes; such data being subsequently played back by the system in such a manner as to cause the musical instrument to reproduce the original performance.

Abstract: A pipe organ in which information relevant to actuation of keys and stops at a console of the organ is stored in random access memory, and the specifications for stops are held in pre-programmed read only memory, the requirements for each pipe being examined in turn by scanning means.

Abstract: A pipe organ in which the operative condition of keys and stops is examined by time-division multiplex techniques to provide digital signals which can be transmitted to a pipe sounding section of the organ and/or recorded for subsequent transmission to the pipe sounding section of the organ, note/stop correlation between keys played and pipes to be sounded being effected by modification of the transmitted digital signals.