Actually I just realized I have seen this girl before...she's "Epic Violin Girl" and has a dubstep violin video and a zelda video.
While I would still hit, I must say--as a former violinist--that dancing while playing the violin on video looks really dumb. These newer videos you posted are a bit better, but some of those old ones just look really awkward. You can't move like that while playing the sort of things she is playing...its just not possible and it is obvious from the bad syncing of the bow with what's being played.
She's more attractive in the videos you posted because she is not moving about awkwardly.