3 is a song by American pop singer Britney Spears, from her second greatest hits compilation, The Singles Collection. It was released on September 29, 2009, as the lead single of the album by Jive Records. The song was produced by Max Martin and Shellback while Spears was on tour in Sweden. "3" is an uptempo dance song, that features a heavy bassline and has influences of electropop and rave. The song's lyrics talk about threesomes while referencing Peter, Paul & Mary during the choruses. .