Pink Floyd's The Dark Side of the Moon is to seal its place in history at the US Library of Congress as part of its National Recording Registry.
Joining it will be Chubby Checker's 1960's dance hit The Twist and Sounds of Silence by Simon and Garfunkel.
Each year, 25 "culturally" or "historically" significant recordings are added to the registry, established in 2000.
Garfunkel, said he was thrilled and flattered to have his work preserved.
His song The Sound of Silence, written after the assassination of President Kennedy in 1963, initially flopped, only becoming a hit after it was re-edited