This looks really cool and I'm excited to play around with it. I had been using Euterpea for a while last year (http://haskell.cs.yale.edu/euterpea/), but as far as I can tell that project has gone cold, and it's a huge pain to get working on an update haskell-platform.

EDIT: Never mind, looks like Euterpea has actually seen some development (and improved documentation) since I last used it.