Generative Music - Anis Haron - Audio Palimpsest
This might not be symphonic piece, but it is an interesting project in a way of aesthetic and mechanism.
Audio Palimpsest is a hacked cassette recorder, interacting with audience by its IR distance sensor. According to the comment, the recorder wind or rewind the tape according to the approach or receding of audience.
Since the recorder is not only playing the tape but It is overwrite or play the tape, (I couldn’t figure out how they decide which.) the installation records the environmental sound of the site unexpected way, and generates sound.
If you ask me about whether we can tell this as music or just mere sound, I can definitely say this is music. Actually it seems like the artists added some way to make musical sound beside recoding the environmental sound only.