By BRETT ZONGKERWASHINGTON (AP) â¿¿ Simon & Garfunkel 's song "The Sound of Silence," written amid the turmoil following President John F. Kennedy's assassination, and Chubby Checker's 1960s dance hit "The Twist" are among 25 recordings selected for preservation at the Library of Congress. These are just a few sounds of the 20th century being added to the National Recording Registry on Thursday for long-term preservation for their cultural, artistic and historic importance. The library said Checker's rendition of "The Twist" became a symbol of the energy and excitement of the early 60s after "American Bandstand" host Dick Clark chose Checker to record a new version of the song. Later, the 1966 album "Sounds of Silence" by Paul Simon and Art Garfunkel was a hit in its day but not before the duo struggled and split early on. Their song "The Sound of Silence" from the aftermath of President Kennedy's assassination 50 years ago this year had initially flopped â¿¿ but it became a hit after it was re-edited as a single. That prompted the duo to reunite and quickly record another album under a similar title. Garfunkel, 71, told The Associated Press he's thrilled and flattered to have his work preserved in the Library of Congress. He said the hit album was a life changer for him and Simon. "Da da dee, da dee, da dee," he sang in an interview. "There's something fundamentally appealing about the simplicity of those lines," Garfunkel said. "When you look at the little mesh, wire microphone ... and you address people on the other side of the mic, you hope that your performance will be special, and you hope that it will have lasting power," Garfunkel said. He said he remembers thinking in the 60s that "if we do really good and give a very special performance to these great Paul Simon songs, we might last right into the next century and be appreciated."