When George Gershwin wrote "I Got Rhythm," he knew that, for generations to come, listeners and performers alike would have a good idea of what he meant. After all, there would be recordings and piano rolls of his actual performances of the piece. Not to mention a standardized notation system to guide future performers. Alas, no such musical preservatives were available to Magister Leoninus in the last half of the 12th century, presuming he would have wanted them even if they had existed. What were his sonic intentions? We'll cover some ....