I had an idea of playing with granular synthesis in Overtone but I had no luck making t-grains ugen work. In the same time I found an excellent PD project called Granita courtesy of Lorenzo Sutton which did everything I wanted.
The problem with PD is it's approach to UI construction which is a real PITA. On the other hand Overtone's way of doing things just rocks. I like to sketch whatever I make with emacs-live and nrepl. It's so much better then anything else for a mixed live-coding, notational composition approach to music making. Both PD and Overtone support OSC communication. My solution is to control PD's patch through OSC from Overtone.
This video shows my current state of affairs.
You can find all the code on GitHub.