Laser harp

In the MIDI controller, this analog DC current interruption is converted to a digital signal, which is then used to trigger many possible events or actions.

Some software comes equipped with full wave file editors and synthesizers, and can also trigger video and still imagery via projection units.

The advantage of a dedicated sensor mechanism is that the instrument can be self-contained, as opposed to requiring a computer to control it with input from an ILDA interface and USB camera.

Furthermore, the gloves protect the player's skin from potentially hazardous laser radiation and give audiences a more visual impression of the instrument.

The image recognition laser harp is also an unframed design, but uses a high-speed USB camera connected to a laptop computer, instead of a photodiode to detect the reflected light from the hand breaking the beam.

The digital picture is analysed by the computer software to determine which beam is broken and send the appropriate MIDI signal back to the synthesizer, which is responsible for creating the sound.

The characteristic sound of the laser harp in Jean-Michel Jarre's performances comes from a factory preset on the Elka Synthex synthesizer.

[6][7] During Jarre's 2009 In-Doors Arena Tour, he commented on his blog that he "should make a few intentional mistakes for people to really understand that it is live".