This collage by Matthias Paulus Kleine (http://www.musikundtheologie.de) contains several well-known works by J. S. Bach (or at least attributed to him). The notorious P.D.Q. Bach also makes a brief appearance.
Matthias Paulus Kleine describes how his idea came about:
"I thought of a music school director who always played the organ on Sundays. At the end of the service, he liked to play the first few bars of well-known Bach works, which then, to the surprise of knowledgeable listeners, suddenly took on the organist's own harmonies and cadences and ended that way. The idea behind this mashup was to refine the music school director's collage technique a little. I suspect that Bach had a sense of humor."