World of Weird Al Yankovic

I have noticed on a few occasions that during a live performance, the backing tracks got out of sync at a random point in the song. Two examples I can think of (because it is on youtube) is during You Make Me, and Polka Face. For YMM, they started out fine, but about a minute into the song, they all of a sudden were 30 seconds behind. Kinda the same scenerio for the polka. Right before "I Kissed a Girl", the tracks of the horns as well as Al saying "tonight" in a deep voice were delayed. In that instance, I noticed you signaling to backstage to cut the tracks, but when Al caught up, you told them to keep it rolling. How does this happen? I always thought the backing tracks were a single file of sounds, but these videos make it seem as if each sound is its very own cue. Sorry for the long question!

The audio tracks were initially not locked for some reason, and it wasn't unheard of for one or more to slip, although I don't recall such an egregious 30-second discrepancy! Later, the tracks were modified so they were locked to each other and the video, and I don't think it's possible for them to be out of sync anymore. However, there may be other glitches such as freezing, which of course means the audio freezes as well. It's worse than just being out of sync! Either way, it's tough to be in my shoes up there, I'm completely at the mercy of the server during key songs!

Bermuda