I think that Gershwin's greatest accomplishment was himself. Just think; in the space of roughly twenty-five years he went from a rough and tumble kid who would rather hang out on the street corners with the "local toughs" than do anything else, to the world renowned composer of "Porgy and Bess", one of the few American operas (maybe the only one at this point) with real staying power. In that period of time he learned how to play the piano like a demon, compose songs that are still as fresh today as when they were written, orchestrate his material in an awe inspiring way, write show after show after show, and in between all of this manage to produce several wonderful pieces of so-called "serious" music (which ARE wonderful in spite of picky things the critics may have had to say about them) and finally end up writing "Porgy and Bess." He produced so much good stuff, so fast, that it is impossible to imagine what he could have done in the next twenty-five years had he lived.