"Single" is the second single from New Kids on the Block's fifth studio album, The Block, which is a duet with Ne-Yo. The lead vocals were sung by Joey McIntyre, Donnie Wahlberg, and Jordan Knight. Donnie also rapped in the song. The song was released on August 12, 2008 as a digital download. According to allaccess.com, the single impacted radio on September 2, 2008. the same day the album was released. The song was released as a CD single in the UK on November 11, 2008. Ne-Yo included a solo version of the song on his album Year of the Gentleman with a length of 4:18.