Recently discoverd Aaron Copland.
What a shame that I have missed out on this for so long.
I wanted o know what some of his best works are, what I should really look for.
Well, the “classics” (in my opinion, at least) are “Rodeo”, “Fanfare for the Common Man”, his 3rd Symphony, and (pardon me for spelling it wrong) “Appalacian Spring”.
Some of my personal favorites are “Billy the Kid” and “The Red Pony” score.
I was lucky enough to see Copland himself conduct, at the Hollywood Bowl. It was a few years (or less) before he died. I think in the early '80s?
Hmmm…I made it look like both “Billy the Kid” and “The Red Pony” are scores. They are not. “The Red Pony” (score for a Robert Mitchum film) is a movie score. “Billy the Kid” is a ballet. Well - perhaps you could call it a “ballet score”?
Anyway, I am glad that you have discovered Copland! He’s wonderful! 
Funny thing is, Copeland was happy enough with Appalachian Spring as a piano-only piece, and when you look at the math/music aspect of the piece, you can see why it’s interesting aplenty just on that level. Agnes DeMille coaxed him ito a full orchestration for her ballet troupe.
BTW Muad’Dib, I encourage you to take a side trip off Copland into Virgil Thompson. It’s similar territory but, to my ear at least, more authentic.
I would add his 3rd Symphony.
I’d add Concerto for Clarinet and Quiet City.
Outdoor Overture. Great song.
And as you listen, you’ll probably realize, “Hey, I’ve heard that!” There a great bombastic bit in “Appalachian Spring” that is shamelessly used by eeryone and his brother from movies, TV, to commercials even. You’ll know it when you hear it.
Sir Rhosis
Yeah, and I defy you to listen to “Rodeo” and not say, “BEEF. It’s what’s for dinner.”
Did they use “Fanfare for the Common Man” at one Olympics, or was it my imagination?
Fanfare for the Common Man
Appalacian Spring
Billy the Kid (ballet)
El Salon Mexico
Rodeo (both the ballet and the 4 selections)
Lincoln Portrait (orchestra with narrator)
“Our Town” soundtrack (movie score)
The Tender Land (opera - rarely performed, but really good)
Welcome to the wonderful world of Copland.