Aldean musical instrument

From Memory Alpha, the free Star Trek reference

The Aldean musical instrument is an advanced device that is controlled by thoughts. The player has to put his fingers on certain pads on the instrument and just feel the notes in his head. If done correctly, the instrument will start to glow in different colors and produce a melody that is similar in mood to the player's feelings and thoughts.

Melian, an aged Aldean musician taught Katie, a child aboard the USS Enterprise-D, how to play the instrument when she was abducted by the Aldeans. (TNG: "When The Bough Breaks")