The classic, justly admired Simon and Garfunkel album, “Bridge Over Troubled Water,” has sold 25 million copies around the world since its release in 1970. But when a newly re-mastered edition came out last year, Roy Halee, one of the disc’s producers, made a startling admission — because the master tapes for the disc were in such terrible condition, the engineers doing the sonic spit-and-polish might have been better off finding a pristine vinyl copy for their work.

For this reason, the Library of Congress deserves to be commended for the National Recording Registry, which seeks to catalog and preserve historically significant sound recordings. Since 2003, they’ve announced a new list annually and the latest batch is a fascinating cross-section of aesthetically and historically important recordings.

It includes a Thomas Edison cylinder from 1888 and Prince’s “Purple Rain” album, which arrived almost a century later. In between, the 1943 New York Philharmonic debut of Leonard Bernstein earned a spot, as did “A Charlie Brown Christmas” from the Vince Guaraldi Trio, and an audience recording of a 1977 Grateful Dead concert.

Part of what makes lists like these so intriguing is debating what’s in, what’s not and what should be. John Coltrane’s “Giant Steps” is included, but not “A Love Supreme.”

Elvis Presley’s “Sun Sessions” is in, but not “Hound Dog.” Chuck Berry’s “Roll Over Beethoven” is in, but not “Rock and Roll Music.”

Come to think of it, “Bridge Over Troubled Water” isn’t in the registry yet, either.

A decade into its existence, the National Recording Registry still has a universe of sound to mine.

— Observer-Reporter,

Washington, Pa., May 29