Bach, Vivaldi, Scarlatti - on an accordion. I have newfound respect for the accordion - at least the button type - as a serious solo instrument. It's one of very few instruments that can play true polyphonic music. String instruments can't really, nor can wind instruments. In fact, only guitar, harp, and keyboard instruments can.
Here is a splendid performance of the Chaconne, marred slightly by some imbecile talking in the middle of the piece. But she plays it beautifully, and technically it's altogether astounding that anyone can play what is obviously a fiendishly difficult instrument that fluently.
The performance begins at about 1:00.