premise: "Moment by Moment" is the title theme song to the 1978 Universal Pictures film "Moment by Moment" starring Lily Tomlin and John Travolta. It is written by Lee Holdridge and Molly-Ann Leikin and performed by American singer Yvonne Elliman. The song is featured twice on the film's soundtrack album, as the first track and reprised as the final track, including three instrumental versions.
hypothesis: Moment by Moment had a different singer for the film.
reason: Its possible the song had a different singer originially