A while back I animated a Foozle.

Specifically, Vibrato, the guitar player from Foozle Bop.

12 frames @ 12 FPS.

Believe it or not, this originally started life as a math problem.
The animation ended up as a proof of concept for it.

Basically, I wanted to work out what Beats Per Minute (aka tempo) would work with what Frames Per Second (animation) seamlessly. The idea being, if you were to make music specifically for animation, what tempo would be the best to use, and how many frames to loop it.

If you think of the tempo as a kick-snare-kick-snare, then frame one would be where the kick drum hits. The midpoint of the animation would be where the snare hits, and then you'd loop back to the kick drum frame again. So, Frames per beat vs beats per minute.

This was what I came up with:

bpm = beats per minute
fpb = frames per beat

== Animating on twos ( 12 fps ):
090 bpm = 8 fpb = 16 frame loop
120 bpm = 6 fpb = 12 frame loop
144 bpm = 5 fpb = 10 frame loop
180 bpm = 4 fpb = 08 frame loop
240 bpm = 3 fpb = 06 frame loop
360 bpm = 2 fpb = 04 frame loop

== animating @ 24 fps:
090 bpm = 16 fpb = 33 frame loop
096 bpm = 15 fpb = 30 frame loop
120 bpm = 12 fpb = 24 frame loop
144 bpm = 10 fpb = 20 frame loop
160 bpm = 09 fpb = 18 frame loop
180 bpm = 08 fpb = 16 frame loop
240 bpm = 06 fpb = 12 frame loop
288 bpm = 05 fpb = 10 frame loop
360 bpm = 04 fpb = 08 frame loop

Using this formula, this animation was timed to 120BPM, aka "the disco tempo."