It's well known that Mozart died long before his time. It's equally well known that his musical life began at a tender age and that his gift saw a remarkable flowering early on. But what were the tiny Mozart's first musical expressions? In his biography of Mozart, musicologist Maynard Solomon tells us that the three-year-old Mozart spent "countless hours" at the keyboard, possibly emulating his older sister, Nannerl, who by then was taking keyboard lessons from her father, Leopold Mozart. When Mozart was four, he composed what might have been listed as K. 0 in the Köchel catalog of Mozart's works: a concerto written in musical notation of Mozart's own devising. Such were the first inklings of the brilliant performing and composing careers to follow.