The first is from a violinist called Gilles Apap, who both looks like and plays like a Gypsy, having his way with Mozart's Violin Concerto. Check this out.
The other is Alfred Schnittke, being not quite so crazy with Beethoven. The Apap performance is on video and you can see that some of the musicians Are Not Amused. I think it's pretty cool myself, even though I love both of these concertos. The Cleveland Orchestra concerts start soon and I would love to see/hear something like this once in a while.