From Wikipedia;

Alfie: Although Burt Bacharach has cited "Alfie" as his personal favorite of his compositions, he and Hal David had not been very interested when approached to write a song to serve as a promotional tie-in with the upcoming film Alfie.

Bacharach felt – in his own words – "with 'Alfie' the lyric had to come first because it had to say what that movie was all about". He arranged for David – in Long Island – to receive a script of the film to facilitate writing the lyrics for an "Alfie" song.

David utilized one of Michael Caine's lines in the film, "What's it all about?" as the opening phrase for the song's lyrics. When completed these were set to music by Bacharach.

"Alfie", recorded by Cilla Black, was released in January 1966 four months prior to the opening of the film. United Artists commissioned a new version of the song "Alfie" by Cher, released at the end of June 1966 almost two months prior to the film's US premiere.

Strange Weirdos: Music from and Inspired by the Film Knocked Up is the official soundtrack album to the 2007 Judd Apatow film Knocked Up, and the eighteenth studio album by American singer-songwriter Loudon Wainwright III, released on May 22, 2007 on Concord Records.