Abstract: There is disclosed a system for encoding of bass and treble expression effects while recording from the keyboard of an electronic player piano wherein the intensity of the music being recorded is reflected in variations in the power of the acoustic waveform produced thereby. The key note or key switch actuations are multiplexed in a serial bit stream of data and stored in a shift register and then separately combined with the bass and treble expression data bits in a format which, upon re-creation of the original musical presentation, results in a more faithful rendition of the original performance.

Abstract: There is disclosed a method and apparatus for encoding of expression while recording from the keyboard of an electronic player piano wherein the intensity of the music being recorded is reflected in variations in the power of the acoustic waveform produced thereby. There is a delay between the time the key is struck and the time that the note is sounded or heard by the listener. The apparatus measures the changes in power by performing a digital integration of a waveform. The key note or key switch actuations are multiplexed and a serial bit stream of data and stored in a shift register and then combined with the expression data bits to form the data stream which is encoded in a bi-phase encoder to be recorded on tape.