I knocked together a quick sonic experiment in Chuck last night that uses the Fibonacci sequence and φ to determine each note's pitch, duration, and vibrato settings. I haven't done much with Chuck in quite a while but was highly pleased how easily the experiment converged (about 15 minutes all told). You can listen to the output here if you're interested: http://lowbroweye.com/post/3284637463/fibonacci-fiddlings And here's the code: http://cdn.lowbroweye.com/misc/fibonacci.ck A.