In 1973, a precocious 15-year-old aspiring rock journalist lands a dream assignment from Rolling Stone to tour with a rising rock band, embarking on a coming-of-age journey as he discovers the exhilarating and heartbreaking realities behind rock stardom.

The now estranged bandmates of Spinal Tap are forced to reunite for one final concert, hoping it will solidify their place in the pantheon of rock 'n' roll.