honestly, I thought that too. but i just think the video/audio sync gets off. the way they come in and out and how they don't seem to stay together leads me to believe that they are actually playing. and if you want to know if i have any credibility in the subject i've been playing violin since I was three years old (yay suzuki method nerd)
Hmmm, but the louder of their foot falls make noises that are clear in the audio, which makes me believe that they have microphones on them that are picking up their playing.
Or were the stomps also synched? Or just edited in?
Whether or not they're playing, in general there's no excuse for standing on a stage and pretending to play music. Either you can perform it or you shouldn't be touring it.
This is absolutely not 'bow-synced'. The audio is not properly synced with the video, which is a common problem with youtube clips.
It would be much more difficult to match all of the many tempo changes and random elements than to just play the thing live. Syncing the long silences would be impossible to pull off, especially in a comedy routine were timing is determined, to a large extent, by crowd reaction. Plus, the performance is sloppy and pitchy (which is perfectly acceptable in a wacky comedy routine) defeating the whole point of playing to tracks in the first place.
Playing to tracks is rarely - if ever - done in the classical genre, because the musicians are talented enough to not need it and the entire point of the genre is live performance, not fashion or choreography. Not to say that pop-classical acts like Andrea Bocelli don't use tracks or enhancement, but you shouldn't be listening to that shit anyway.