I am having alot of trouble understanding this.

If i am shooting a music video at 60p but i will be rendering out to 24p for the final product. How do I keep the audio in sync? Do i need to have the song play at a faster or slower rate as I am filming? Or do I speed it up or slow it up in post?

Also, If i shoot in 60p and render out in 60p but upload it to youtube which will play it back at 30 or 24p. Will the audio be out of sync or will youtube automatically convert the audio to be in snyc with the 24p or 30p playback?

Thanks!

You do not change the speed of the action, by changing the framerate. Instead you are skipping or transcoding the existing frames with something called pulldown. In effect each remaining frame, stays visible longer.

The audio will not be affected by this.

However I would urge you to record at the framerate that you intend to deliver the finished product in.

So your saying if I film at 60p then render out to 24p that the audio will be in perfect sync with the video?

Reason I will be shooting in 60P is due to a ton of slow motion

To play back in slow mo, but have the lips sync as if in time with the song, you need to play back the song fast and have the performer lip sync to the fast version.

As a reference 60/24 = 2.5, so you would need to have your performer singing the song at 2.5 times speed for the sync to be about right.

Here is a music video I produced and edited that uses that effect:

YouTube - ‪My Favourite Thought - Donald Reid (720p HD)‬‏ (http://www.youtube.com/watch?v=sLte8ipwouI)

(In this example it was all shot slow mo, and then speed ramped in post so that I could ramp up and down the frame rate.)