Music by Irish rock group U2, jazz musician Art Blakey and rock-'n-roll singers the Everly Brothers are among 25 sound recordings being added this year to the U.S. Library of Congress' National Recording Registry. The Library of Congress, the nation's oldest federal cultural institution, preserves the best existing version of each recording on the registry. "These recordings represent an important part of America's culture and history," Librarian of Congress James H. Billington said in a statement. "As technology continually changes and formats become obsolete, we must ensure that our nation's aural legacy is protected." The list includes U2's 1987 album "The Joshua Tree," the Everly Brother's 1960 hit "Cathy's Clown," Blakey's "A Night at Birdland" album from 1954, and the original 1979 recording of the musical "Sweeney Todd" by Stephen Sondheim and Hugh Wheeler.