A while ago I got a Flightaware Pro Stick Plus - a neat little software-defined radio that lets my little Raspberry Pi Zero decode ADSB transmissions from aircraft. These transmissions broadcast the location and altitude of each aircraft, in addition to other data.
So, I thought, why not turn those transmissions into music?
Code (evolving work, is a bit messy): https://github.com/ggood/adsbTheremin
General idea: python code reads the stream of aircraft position reports and creates a map of where the aircraft are and their distance/altitude relative to my location. Then map this information to MIDI note on/off events and send this information to Ableton Live running on my Mac.
Listen to the long notes - lower pitches are aircraft at low altitudes, higher pitches are aircraft at higher altitudes. At about 2:50 you can hear the general aviation aircraft doing touch-and-goes at the Palo Alto Airport (low tones), while the commercial airliners pass overhead, with much higher pitches.
There is a lot of arpeggiation (jumping-around notes) to keep things interesting, but the long notes you hear represent the position and altitude of the aircraft.