Chamberlin Riviera #0001. This is one of 2 units built and Harry Chamberlin's personal instrument. This is an M series model with 1/2 inch 8 trk tape, stereo outputs from 5 different subassemblies. The footpedals are connected to contacts that fire electro-magnetic solenoids. These solenoids pull the "keys" of a 25 note rhythm unit. Each foot pedal contact also has a capacitor that keeps the circuit closed until the players foot has played another pedal, this was done to allow for a legato change from one pedal to the next...and it works!