A device non-integral with the keyboard instrument with which it is used is activated through sheet, card or substitute keyboard means to activate in turn indicating heads mounted over the keyboard of an organ, piano or similar instrument and which designate the keys to be played by lighting or solenoid controlled means. The control sheet or card may utilize raised, indented, or apertured sheets or cards detected through various type contact or photocell means which feed the signal through an elelctronic relay to the indicating means.
A control sheet or card having raised portions thereon for operating a contact with the raised portions shaped for guiding and centering the contact as the raised portions pass by the contact with inwardly sloping forward and rear ends on the raised portions.
