Aaron Copland is probably the best known American composer of classical music with many great pieces, so far I've only done a write-up on his Third Symphony.
Copland's Third Symphony is one heck of a great symphony, one of the great symphonies of all time featuring an American spirit of optimism, openness and freedom, qualities not found in European works. This ADD version has never been equaled as far as I know. The DDD version with Bernstein conducting the New York Philharmonic on DG is inferior, I think at least because of the engineering. A DDD version that is almost as good is Yoel Levi conducting the Atlanta Symphony Orchestra on Telarc but it still lacks some of the beauty and the passion of this old Sony (Columbia) version. There are other recordings I have not heard. The Symphony for Organ and Orchestra on the Sony CD is pretty unremarkable.