This basic rule of acceleration and deceleration of an action also applies to a musical background,

- The animator must constantly be aware of beats and accents. And there is no accented position, when action is all evenly spaced.

- NOTE: The faster the beat, the more accurate the hit or accent must be.

- A beat constitutes a specific interval of time. It applies to both the musical beat and action tempo. A 24 beat means 1 beat per second or every 24 frames.

- The measure of time established by the musical tempo must be broken down into audible taps. A metronome is normally necessary to measure the rhythm.

- A 12 beat action would be equivalent of 2 taps per second. If the tempo quickens to an 8 beat, this represents 3 taps per second. Only violent action will require anbimating as fast as an 8 beat.

- Accuracy is especially important if the beat is faster than a 9 beat. The hit must occur exactly on the cue frame which receives the tap.

- This applies also to rapid dialogue. The mouth positions must occur exactly on the frame of the corresponding sound. And the action must change on every frame. Animate in ones.

(When a slower beat is used, such as a 12 or 16 beat, the accented action may hit two frames before the frame of the tap. Greater impact is also provided through extended contact).

- When the rhytm of the dialogue is relaxed and conversational, the lip movements should be started two frames ahead of sound. Depending on phonetics, it takes one or two frames to form certain letters before sound is spelled.

- Remember: the faster the beat, the more accurate the accent - and the lip movement must be synced exactly as indicated on the exposure sheet.

- These rules also apply to sound effects.