Rocker Billy Joel performed a unique take of The Tokens' The Lion Sleeps Tonight with U.S. Tv host Jimmy Fallon on Thursday night (20Mar14) by using a new iPad app called The Looper, which records the user's voice and loops it to create a vocal group harmony. The app allowed the duo to sing multiple parts of the same song and put them together to form a doo-wop version of the track, backed by house band The Roots.