................In order to give a homogeneous polyphonic sound, the SEM's had to be individually programed to the same sound, and this combination was stored in a programmer that had 16 locations.

If you had different sounds in each SEM, you could assign the instrument to move sequentially through the SEM's in turn, or remain "frozen" on one, or remain on one for the first note played, and then step through the other three....you could also split the keyboard.

Ian