I have always loved the Ave Maria that Charles Gounod wrote as an obbligato above J.S. Bach's C-major Prelude, BWV 846, from the Well-Tempered Klavier, so I fashioned my own obbligato atop another Bach Prelude, the Prelude BWV 999 in C minor.
I just put a pdf of the music (that you can download, if you want) as well as half computer-generated audio recording of the resulting piece, which I call Cloud 999, on my American Music Center page. (The violinist is not computer-generated: its me.)
New Update: The first Mp3 is blank (it was a totally computer-generated recording that I have now removed), so make sure to click on the second one.