I'm just starting to get into this, and yes, it is a ton of fun. I started out using Tidal, now I'm moving onto Overtone (a Clojure library for making music) because it's more about synths and scales than Tidal, which is more about loops and samples. 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.
How did you learn Overtone? I've used Emacs a bit but never Clojure. How would you recommend getting started?
Edit: If you just want to basics, this should work for you: http://seabre.github.io/blog/2013/08/31/a-simple-livecoding-...