This is a common myth [1].
[1]: http://conal.net/blog/posts/everything-is-a-function-in-hask...
Someone who believes the myth and is aware of Church encodings probably thinks everything is Church encoded in Haskell. Someone who believes the myth and is not aware of Church encodings will likely have no mental image to associate to Haskell, and feel it is truly alien.
(I have a friend who always tries to show me examples of neat stuff he's done in Haskell and I can never wrap my brain about it)
I usually like to say "just about", "informally" or "while there are some exceptions, it can be helpful to think about it as if..."
Both of them are great though. Whichever you get into just depends on what you want to do. Overtone integrates with midi really well too.
Edit: If you just want to basics, this should work for you: http://seabre.github.io/blog/2013/08/31/a-simple-livecoding-...