This is part of the disquiet junto series. Disquiet0005 is about amplifying the inherent musicality in reality. Right up my street ;-)
Here I took a recording of Liverpool Street station and built a patch using Pure data and the RjLib to analyse the recording in realtime. The patch then decides, based on many rules I put in there, when and how to play certain notes and sounds.
The percussive short tuned percussive synth sounds are based on each time there is a ( even tiny ) sharp attack sound. The pitch of the note is determined by how intense the sound is. The higher the intensity the higher the pitch.
The bass determined by an averaged frequency analysis, over a threshold it will decide to play a note.
Drums are determined by pitch change events in the frequency analysis, and only occur over a certain volume threshold of pitched data. There are quite a few rules for when various repeat events should happen too.
The fast synth during the announcements is attempting to track the melodies in the voice and mimic them.
Each of these analyses is quantised into a musical scale and timing in various ways. I tried to work out what key reality was in at this point :)
I will be releasing an interactive version of this as an RjDj scene soon. This way it will run live on your iPhone / iPod Touch and make music based on the live input from the microphone.