"Sing" is a song recorded by British singer Annie Lennox for her fourth solo studio album, Songs of Mass Destruction (2007). It was released as the second single from the album on 1 December 2007 by RCA Records. Lennox was inspired to write the track after seeing South African activist Zackie Achmat at Nelson Mandela's 46664 HIV/AIDS concert. She wanted the track to be a source of empowerment for people without a voice of their own. It also gave rise to her SING Campaign which aimed to raise funds and awareness for issues surrounding HIV/AIDS. "Sing" was produced by Glen Ballard and interpolates the South African tune "Jikelele"; the music was given to Lennox by an activist group called The Generics.

Lennox personally invited other musicians and singers to work on the track. Ultimately 23 singers were enlisted, who recorded guest vocals on the chorus of the song in different locations. Among them, American singer Madonna also sang the second verse. "Sing" was accompanied by a number of remixes released on the same date. A music video was also released to promote the track. Lennox also performed it throughout the United States as part of her SING campaign. Music critics noted the empowering and anthemic nature of the track, recalling Lennox's previous work. It had minor chart placements on the UK Singles Chart, and the US Adult Contemporary and Dance Club Songs charts.

Lennox was attending a benefit held by former South African president Nelson Mandela's 46664 HIV/AIDS campaign in 2003. There she was surprised to see a man wearing a black t-shit with the message "I am HIV positive" written in capital letters. She found it to be a bold statement and inquired about the man, who turned out to be Zackie Achmat, a South African activist, film director, and co-founder of the Treatment Action Campaign (TAC). Although the singer had been associated with the 46664 campaign, being introduced to Achmat gave her an opportunity to do more for the campaign and the project.

...
Wikipedia