Té Rowan - For that first one of Cotton Eye Joe, I always liked the Rednex version.
There is something supremely funny and ironic about a modern Swedish band pretending to be a old style U.S. Civil War era Kentucky Bluegrass hillbilly style band...
Rednex - Cotton Eye JoeRednex - Old Pop in an OakRednex - Wish You Were HereAlso, came across the following AMV this morning on AMV.ORG... but since most here prefer YouTube Videos...
HSOTD 'HighSchool of the Dead: Thriller 2014' by ClaudiusValentine
EDIT1: Had to adjust my old links, since all were dead since last checked...
EDIT2: As for Violinists... my brother introduced me to this one a while back...
Lindsey Stirling - Master of TidesLindsey Stirling - Moon TranceLindsey Stirling - Shatter MeLindsey Stirling - Stars AlignThere is also the following violin centric AMV I liked:
SM 'Poker Face - Outer Senshi' by DarkelementAngel