The biggest hole is where the light beam comes out. The two small are the sensors measuring reflected light. The sensor closest to the light look straight into the beam sensing all reflected light. The other one is tilted so it can only see the lower part of the beam so that the harp can see if your hand is in the lower or upper area. High area plays the tone one octave higher then low.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s