IIRC, early copyright (say, during Mozart's time) required royalties to only be paid out for the first performance of a work. And that is why some of these com

IIRC, early copyright (say, during Mozart's time) required royalties to only be paid out for the first performance of a work. And that is why some of these composers were so prolific - to keep up their payday, they had to crank out music instead of collecting on royalties of performances they were directly involved with. Unthinkable today, really.