“What Are You Doing the Rest of Your Life?” has become a song closely associated with Barbra Streisand, and she has even included it in some of her concerts over the years.

The song was written by her friends, Marilyn and Alan Bergman, for a film directed by Richard Brooks — The Happy Ending (released December 1969).

Brooks asked the Bergmans to compose a song to be used twice in the movie: at the beginning when they plan marriage, and at the end after splitting up. “And he said, 'I don't want you to change a note or a word, but I want the song to mean something very different when you hear it the second time,’” Alan Bergman said.

Michel Legrand wrote the music for the picture. While sitting with Legrand, the Bergmans asked what “happens if the first line of the song is 'What are you doing for the rest of your life?' And he said, ‘Oh, I like that,’” Marilyn Bergman said. “And he put his hands on the keys, and as long as it takes to play that song, that's what he played from beginning to end, and he said, 'You mean something like that?' And we said, 'No, we mean exactly like that.' And Alan said to him, 'Play it again.' And he said, 'Oh, I don't remember quite what I played.' Luckily, we had the tape machine going, so we had the music. And then we zipped through it.”

Alan Bergman told The Los Angeles Times: “Barbra came over for dinner, and we had just finished the song that day,” he recalled. “It was on the piano and she passed the piano and saw the title — Michel was staying with us — and she said, ‘I like the title, can I hear it?’ So we sang it to her and she said, ‘Let me hear it again.’ She said, ‘Let me sing it.’ We have on tape the first time she sang it and it’s all there, every nuance.”

Bergman continued the story, as told to Billboard Magazine. ”Then she offered to sing it in the film. We told her that the director, Richard Brooks, wanted it sung by an anonymous male voice. Barbra said, ‘I'll sing it anonymously.’ We weren't sure how to tell Barbra that it would be very difficult for her to sound (A,) Male and (B) Anonymous! So we left it to Richard to dissuade her. But she did record the first single.”

The single (b/w “What About Today?” from Barbra's July 1969 album with the same title) was released October 1969. “What Are You Doing the Rest of Your Life?” would remain available only as a vinyl single until Barbra put it on her 1974 studio album, The Way We Were.

This single did not chart, either.