That'll Be The Day stars David Essex as Jim MacLaine, a young man in search of his own identity. The film is based on Nilsson's song "1941" and also has some parallels to the life of John Lennon. The movie begins in the late 1950's with MacLaine's father abandoning his family after WWII (a theme which I have seen in several British films set in this era) and ends in the early 1960's with MacLaine abandoning his own family for the world of rock and roll.
After dropping out of high school, MacLaine works a number of dead end jobs, and while working as a barman at a holiday camp he meets Mike (Ringo Starr) who becomes his mentor. Ringo is superb in his part, as good as any other actor in the film. I imagine his familiarity with the era helped a lot in making his character so believable. Billy Fury plays Stormy Tempest (based on Rory Storm) in the house band at the camp's bar. The drummer for the band is Keith Moon of The Who, who also has a small acting part. Moon has one of my favorite lines in the film, when asked if he has ever thought about writing his own songs, he replies "you got to be American to write Rock and Roll songs".
Most of the music in That'll Be The Day is on the soundtrack (comparable to the American Graffiti soundtrack), but besides the Stormy Tempest band, there are only two other bands in the movie: a Trad Band and an early rock and roll band (featuring Eugene Wallace as the lead singer). After seeing the rock and roll band, MacLaine/Essex buys a guitar and the film abruptly ends, and MacLaine's story is continued in the film's sequel, Stardust.