Looks really nice, I'll be sure to try it out!
For people interested in this, there's also a recent project https://github.com/overtone/overtone which looks similar, using Clojure though (which seems to deem itself better to live programming).
There is also Andrew Sorenson's [1] Extempore [2] which is also a Lisp.
Yep. In fact, lisps tend to pop up quite a bit in livecoding (and in other places, really).
https://github.com/toplap/awesome-livecoding is a nice curated list of live coding languages and tools.