Mozart and Bach

Here is a scene I would have loved to seen in the movie Amadeus. In Christoph Wolff's excellent recent book on Bach he recounts the following story (quoted from the New Bach Reader) about a visit Mozart paid to Leipzig in 1789, where Bach had been music master in the St. Thomas Church:

the choir surprised Mozart with the performance of the double chorus motet Singet dem Herrn ein neues Lied by Sebastian Bach. Mozart knew this master more by hearsay than by his works, which had become quite rare; at least his motets, which had never been printed, were completely unknown to him. Hardly had the choir sung a few measures when Mozart sat up, startled; a few measures more and he called out "What is this?" And now his whole soul seemed to be in his ears. When the singing was finished he cried out, full of joy: "Now there is something one can learn from!"