Symphony No.7 by Peter Mennin (1923-83) dates from 1963 and was premiered early the following year by the Cleveland Orchestra (commissioner) & George Szell who also brought it to the New York Philharmonic in the April (below). Jean Martinon & the Chicago Symphony made the first recording, for RCA, released in 1968.
Chicago/Martinon…
New York Philharmonic/Szell…
https://www.youtube.com/watch?v=TgpR1SVBShY
As a musicologist who specializes in the American symphonic music of the mid-20th-century, I would assert that Mennin’s 7th is, arguably, THE Great American Symphony. The neglect of Mennin’s music is regrettable and hard to fathom. Unfamiliar with Mennin’s work? Just 5 compositions will do the job: Symphonies 5-7, Piano Concerto, and Cello Concerto.