M-Audio ProKeys Sono +. M-Audio ProKeys Sono ProKeys Sono 61, MIDI + Audio Keyboard Controller from M-Audio in the ProKeys series. Its appearance might lead you to suspect otherwise, but the ProKeys Sono isn't a typical MIDI controller keyboard. It's a cross between a stage. M-Audio's ProKeys Sono 61 keyboard gives you a powerful all-in-one writing, Assignable modulation wheel and voice volume control; Pitch bend wheel.