This interface is made with an old PS2 computer keyboard. The keyboard is linked to an arduino and sends the datas to max/MSP via the Serial port to control sound. A sheet of paper, covering the keyboard, allows to draw the interface. Its flatness allows it to be used as a low resolution touchpad, wich is used here to control the envelop of a filter. The software also allows to control a sequencer, and other parameters like the frequency, a vibrato, and a delay.