Walkers, subway riders, and drivers often listen to songs as the soundtrack to their journey. Wonder what it would sound like if my commute actually made music for me -- if my paths formed notes and beats, would i like the song?
While not music-fying real journeys, Isle of Tune's visual interface makes music from street layouts (placement of roads, lights, trees, houses as the sound elements and movement of cars as the needle). This is the one I made (should have added one more car). Closer to reality, mta.me turns NYC's subway (1972 version) into a "real-time" instrument. Each train line generates a string (length determines pitch). Using data from MTA's public API, the trains head towards the end of their line at a speed estimated according to trip schedules (more detail). The subway's song is actually quite lovely. I especially love the strumming effect.
Haven't tried it, but those looking to quickly prototype music apps for the iPhone or iPad might want to check out iRTcmix, port of older RTcmix music/DSP language to iOS and a Max/MSP environment.