The Meta Trumpet is developed by Johnatan Impett. A traditional trumpet was instrumented to record performance gestures, and converted these to MIDI. Described by CJ Bolland (.ppt) as:

Traditional instruments can be adapted into MIDI controllers for multimedia by incorporating additional sensors without compromising the usual interaction mode. Jonathan Impett’s Meta-trumpet (top) is a good example, breath & pressure sensors, switches, tilt sensors have been incorporated into the instrument without adding significantly to the players cognitive demands.

Some songs .(mp3): 1, 2 or 3 Breathing and using the valves... another way to interact with a machine...