The Ave Maria melody was written on top of Bach's Prelude No.1 in C BWV 846 from his Well-Tempered Clavier, originally for solo piano. Gounod and Pierre-Joseph-Guillaume Zimmerman, his father in law, had partnered in the creation of this work of art. With Charles Gounod improvising and Mr. Zimmermann transcribing the melody. This Ave Maria is not to be confused with Schubert's Ave Maria.