"Sing" is a 1971 song written by Joe Raposo for the children's television show Sesame Street. In 1973, the song gained popularity when performed by the Carpenters, who made it a #3 hit on the Billboard Hot 100. Raposo was one of the staff songwriters on Sesame Street, and the song became one of the most popular on the program, sung in English, Spanish, and sign language. In its initial appearance, the song was sung by adult human cast members of the show (the most frequent lead singer was Bob McGrath) and Muppets, including Big Bird.