Timing music to animation

With the GiveMeTac Metronome, I discovered that the tempo of the song I am syncing to was 120 beats per minute. At 24 frames per second that is a 12 frame beat. I was working at 12 frames per second making it a 6 beat. The rhythm of the song is I beleive is a 2/4 (I could be mistaken but that is the rhythm I timed the animation to and it seems to work). The cycle is twelve frames of Prissy swinging her hips back and forth. The accent is on the 2nd beat which falls on the12th frame. On the accent Prissy snaps her fingers. It syncs up to the accented beat in the song! This is my first success in setting an animated rhythm. Now that I finally understand this concept, I can apply it to all my animations, whether synced to music or not. The metronome can help me time things out in my head much more presicely than a stop watch. I had been using rhythms in my walk cycles as long as I have been doing them but it was not synced to any specific beat (as far as I knew at the time). I knew animation has been being musically timed since its roots, but I simply couldn't figure out how to do it. Both Seamus Culhane's book Animation: Script to Screen, and Harold Whitaker, and John Halas' book Timing for Animation (both of which essential books for anybody who wishes to study animation) have great secions on timing animation to music. However, neither book gave a formula for figuring out how many frames to a beat. Here is an example from Timing for Animation: "Bars can contain various number of beats and these must be measured to the film frame." It does not say how one actually goes about doing this. Fortunately animator Mark Mayerson was kind enough to post the formula in his blog. This discovery takes alot of the guess work out of timing. Before this I timed my animation by feel, and trial and error; hoping eventually I would get a better feel for it over time. Now I can use the metronome as an aid to give me concrete measues of time that I can convert to frames.