Back in the 1980s, Alex Fletcher (HUGH GRANT) was a member of PoP, a hugely successful pop group. But when the band's other singer left with their latest songs, PoP disbanded. Now, and despite the efforts of his manager, Chris Riley (BRAD GARRETT), the best Alex can do is perform at high school reunions and amusement parks when not receiving offers to appear on a reality TV program featuring other '80s has-beens battling for the right to sing again in front of a national audience.
His best shot at resurrecting his career, however, comes from the unlikely source of sultry pop star Cora Corman (HALEY BENNETT) who's a big fan of his. She wants a new love song for her latest album, but has extended that offer to others as well. With only a few days to deliver, Alex is in a quandary since he's never been that good at writing lyrics.
His good luck continues, though, when he discovers that the young woman sent to tend to his plants, Sophie Fisher (DREW BARRYMORE), has a natural knack for coming up with catchy song phrases. Unlike her married sister Rhonda (KRISTEN JOHNSTON), Sophie isn't star-struck by Alex, and she initially declines his request for help.
And that's because her confidence has been shot ever since her former professor-turned-lover, Sloan Cates (CAMPBELL SCOTT), used her and their affair as the basis for a successful, if barely fictitious novel. With a movie adaptation now in the works, Sophie doesn't think she's up for the job. From that point on, and as an attraction develops between the two, Alex tries to convince her that co-writing a song for Cora is the best thing she could ask for, all as he realizes this might be his last shot to return to the big time.