Mozart's liberation of Miserere
In case you don't know this story, Mozart risked excommunication from the Catholic Church when he memorized and wrote down Antonio Allegri's Miserere. By papal decree, this was the punishment for copying the work or performing it outside Rome. However, the Pope was so impressed with Mozart's ability to memorize the work on a single hearing that he bestowed upon Mozart the Cross of the Order of the Golden Spur, instead of punishing him. What a shrewd move! Fancy going down in history as the Pope who excommunicated Mozart! And now we can all enjoy Miserere.