Duo’s sound is huge hit today in 1965

This American music duo’s song hit number one on the Billboard chart today in 1965, the first success for the struggling band.

They went on to become one of the most recognised and beloved duos of all time, but not without hardship – their debut album (containing this song) was a flop and broke up the two singers.

But once this song gained traction overseas, they reunited and recorded their second, more successful album, named after this track despite not featuring it in its track listing.

In 2013, this classic folk rock song was added to the National Recording Registry in the Library of Congress for being “culturally, historically, or aesthetically important”.

Can you guess what this song is?

Listen to “The Sound of Silence” by Simon & Garfunkel below: