Musician Robert "Fish" Fishman (Rainn Wilson) is fired from Vesuvius, a fictional '80s hair band, before they become famous. The movie follows him as he gets a second chance at fame when he joins the garage band of his nephew Matt (Josh Gad). His love interest (Christina Applegate) is the mother of the band's guitarist, Curtis (Teddy Geiger). Pete Best, a former member of The Beatles who suffered a similar fate, has a cameo role in the film as himself.

Majority of the songs found on The Rocker OST are sung by pop singer Teddy Geiger, best know for the track “For You I Will (Confidence)”.