Tags: Clojure, Overtone, Music

Today I'm watching Overtone and ClojureScript which is a coding session of someone setting up an web UI to play Overtone stuff. Building a UI like this reminds me of the one-string guitar that I got at an art festival the other day. Clearly home-made, including an energy drink as the echo chamber. And very awesome. Also fun to see someone iterate through their development. Lots of interesting things in there, most of them I can read more or less but doesn't mean I could write them. One thing I noticed was (:use ...) to pull in instrument libs. I'll try that.

The Cheat Sheet is interesting, but I don't know enough to actually use a lot of the things on there. Current mission is to get the instruments working.

Ah! I need to do (use 'overtone.inst.piano) not (:use overtone.inst.piano).

• Now (piano) plays a note!
• (odoc note) shows that it takes a bunch of params
• (piano 60), (piano 65), etc plays some nice piano notes
• I looked up named parameteters in clojure. (piano 65) does what I want
• Achievement unlocked ... I can now use all the intstruments on the cheat sheet!
• Now when I do "(piano 60) (piano 65) (piano 69)" (still in REPL) it plays all three notes at once. Need to learn how to sequence things.
• I think I'll go back to that workshop video
• At 13:40 they talk about sequencing things
• Play a piano note in 1 second (at (+ 1000 (now)) (piano))
• From their tutorial, I created:
  • (defn loop-beats time (at (+ 500 time) (kick)) (at (+ 1000 time) (open-hat)) (apply-at (+ 1500 time) loop-beats (+ 1500 time) ))
  • (loop-beats (now))
  • (stop)
  • I don't know exactly what that last is for. (odoc apply-at) says it is "argseq" but gives no explanation.
  • In general this is "temorial recursion" -- delays a bit before calling back
  • As far as I can tell this does create new stack frames! Will eventually run out. I know this because I accidentally put the loop-beats recursion in parens which invoked it.
• Following the tutorial, I transformed it to use a metronome:
  • (def metro (metronome 180))
  • (defn loop-beats m beat-num (at (m (+ 0 beat-num)) (kick)) (at (m (+ 1 beat-num)) (open-hat)) (apply-at (m (+ 2 beat-num)) loop-beats m (+ 2 beat-num) ))
  • Get it started: (loop-beats metro (metro))
  • Change the temp live! (metro 200)
  • Stop it (stop)
• Instruments take 'notes' (midi numbers), though some things take hz
• Symbolic notes can be turned into midi numbers via (note )
• Can map a sequence of symbolic notes to midi numbers (map note )
• Now I can make a general purpose play-note-sequence function. I'll just make it play on the beat.