The movie opens with the tragedy-stricken childhood of Dewey Cox, who accidentally kills his brother in a machete accident. This event casts a long shadow over Dewey's life, leading him to promise his brother that he will become a great musician. His early life is troubled, as he rebels against his father’s disdain and society's expectations. Dewey's journey begins in earnest when he discovers his love for music and natural talent. He quickly rises from performing in local bars to gaining national attention, navigating the evolving music scene with his unique sound that spans across multiple genres. Dewey's ambition is fueled by his need for approval and redemption, making his rise to fame a quest not just for success, but for personal absolution.

As Dewey’s fame grows, so do the complexities of his life. The pressures of stardom lead him into a tumultuous love life and struggles with addiction, mirroring the lives of many music legends. His marriage to his singing partner presents a facade of happiness, but behind the scenes, Dewey battles personal demons and professional challenges. His life is a rollercoaster of highs and lows, reflecting the volatile nature of the music industry and the personal cost of fame. His story encapsulates the quintessential tale of rock ‘n’ roll excess, exploring themes of redemption, the destructive nature of celebrity, and the relentless quest for musical immortality.