An organ performance supporting device which has means for detecting ON signals of actuating switches of combination units to provide control code signals, means for setting signals indicating the individual operative states of the switches by the switch-ON detecting signals, a read-only memory for storing coded control signals necessary for the presetting and selection of registrations, the coded control signals being selectively read out in reply to the detected control code signals, a combination registration memory composed of a writable memory and a read-only memory, the combination registration memory storing registrations required by the combination unit and selectively read out in reply to the detected control code signals, a register supplied with a signal from a stop switch and reading out the writable and read-only memories in a predetermined operative state to store the state of the combination unit and the ON-OFF state of the stop switch, a register for storing the registration output from each combination unit for synchronization with an external system, and means for indicating the state of each combination unit and the ON-OFF state of the stop switch.