"Solitaire" is a ballad written by Neil Sedaka and Phil Cody. Cody employs playing the card game of solitaire as a metaphor for a man "who lost his love through his indifference"—"while life goes on around him everywhere he's playing solitaire". The song is best known via its rendition by the Carpenters.

Neil Sedaka recorded "Solitaire" as the title cut for a 1972 album recorded at Strawberry Studios, : 10cc members Lol Creme, Kevin Godley and Graham Gouldman accompanied Sedaka while Eric Stewart also of 10cc engineered the session. Appearing on 1972 album releases by both Tony Christie and Petula Clark, "Solitaire" had its first evident single release in February 1973 as recorded by the Searchers; however it was an autumn 1973 single by Andy Williams which would reach number 4 in the UK and afford Williams a number 1 hit in South Africa. The title cut from an album produced by Richard Perry, Williams' "Solitaire" also became a US Easy Listening hit at number 23. In 1974 Neil Sedaka's 1972 recording of "Solitaire" was included on his comeback album Sedaka's Back. Later in 1975, a live-in-concert version recorded by Sedaka at the Royal Festival Hall was issued as the B-side of The Queen of 1964. This is the version of "Solitaire" that was released as part of Razor & Tie's 2007 Definitive Collection album.

The Carpenters recorded "Solitaire" for the 1975 Horizon album; Richard Carpenter, familiar with the song via the versions by Neil Sedaka and Andy Williams, was "not crazy" about the song but felt it would showcase Karen Carpenter's vocal expertise and Richard Carpenter would assess Karen Carpenter's performance on "Solitaire" as "one of [her] greatest" adding "she never liked the song [and]...she never changed her opinion."

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