At least your father's favourite composer wasn't named Butch.
I wasn't named after Messiaen by the way.
Sorry to digress briefly, but does anyone here know whether our Sir Barrett was named after Wagner or after Strauss?
I fear that the case of Copland is not unakin to that of Rakhmaninov years ago (though admittedly by no means to the same extent), in that most people know him through only a disproportionately few of his works. I have only heard about half of his known output over the years and I have to say that, much as I respect him (how could one not?), there is little of it that truly excites me. Copland was obviously a most important figure in American musical life and will surely always be remembered for that; he did much to encourage interest in and promote the music of his fellow American (sorry for that Reaganism!) composers and put American music on the 20th century map.
It is well known that he wrote Appalachian Spring on the Carters' dining room table and that their friendship, such as it was, seems not especially to have been adversely affected by Copland's increasing lack of sympathy and understanding of the ways in which Carter later developed (he must have had quite a substantial rethink before he paid so fulsome a tribute to his younger colleague around 1970).
Carter's work in the 1930s concentrated quite heavily on writing about others' music and, in those days, he was one of Copland's rather more vociferous champions; this, of course, was in the days before Carter's own compositional activities took over from his critical work.
Obviously, certain of Copland's work is likely to reach far wider audiences more easily than certain of Carter's will do; that said, however, I have never yet encountered anything of Copland that has the depth, expressive range and sheer substance that inform (for example) Carter's Variations for Orchestra, Concerto for Orchestra,
Three Occasions, Symphonia, etc. (but that's just a personal opinion, of course).
Best,
Alistair