Not In National Film Registry Library of Congress
Really? But "Clerks" (1994) is?
https://www.loc.gov/programs/national-film-preservation-board/film-registry/complete-national-film-registry-listing/
The Sound of Music and My Fair Lady are there, so it doesn't have to do with something being a stage production before the film...
Also, the original Rock Opera is not in the National Recording Registry. But the soundtrack to "Star Wars" is.
https://www.loc.gov/programs/national-recording-preservation-board/recording-registry/complete-national-recording-registry-listing/
The Sountrack to "Hair" is listed there also.
"The Who Sings My Generation" and "Dark Side of the Moon" are on the list and those were recorded outside the USA. I don't see any Beatles albums...