In Springberry,
Alabama, 1946, young Dewey Cox accidentally cuts his brother Nate in half with a
machete. His father blames him for Nate's death and the trauma causes him to
lose his sense of smell. Dewey meets a
blues guitarist who discovers his life experience instilled in him a natural affinity for playing blues. In 1953, Dewey performs at a school
talent show and drives the crowd wild with his song "Take My Hand", and his father kicks him out of the house, calling it the "
Devil's music". A 14-year-old Dewey leaves Springberry with his 12-year-old-girlfriend Edith; they soon marry and have a baby. Working at an all-
African American nightclub, Dewey replaces singer Bobby Shad onstage and impresses Jewish record executive L'Chaim. While recording a
rockabilly rendition of "
That's Amore", he is berated by an executive. A desperate Dewey performs "Walk Hard", a song inspired by a speech he gave Edith, which restores the executive's religious faith and rockets him to superstardom. The song quickly becomes a hit and Dewey becomes caught up in the rock 'n' roll lifestyle. He soon performs his first concert as the following act to
Elvis Presley,
Buddy Holly, and
The Big Bopper. Dewey is introduced to
marijuana by his reluctant drummer Sam and becomes unfaithful to Edith. Dewey's father informs him that his mother has died while dancing to Dewey's song and blames Dewey's music for her death. Distraught, Dewey finds Sam using
cocaine and partakes, resulting in a cocaine-fueled
punk rock performance.
Choir-girl Darlene enters Dewey's life, and he produces several sexually suggestive hit records amid their courtship. He weds Darlene while still married to Edith, which leads to both women leaving him, after which Dewey purchases drugs from an undercover cop. After he serves time in prison and in rehab, Darlene returns. They move to
Berkeley, California in 1966 during the
counterculture movement. Dewey's new singing style is compared to that of
Bob Dylan, which he angrily denies despite his new songs and style clearly imitating Dylan’s. On a band visit to
India, Dewey takes
LSD with
the Beatles, leading to a
Yellow Submarine-esque hallucination. Dewey becomes consumed with creating his masterpiece
Black Sheep (a homage to
Brian Wilson's
Smile). The band resents his insane musical style and abusive behavior and breaks up; Darlene, also unable to deal with him, leaves him for
Glen Campbell. During another stint in rehab, Dewey is visited by the ghost of Nate, who ridicules his self-pity and tells him to start writing songs again. In the 1970s, Dewey now hosts a
CBS variety television show but is unable to compose a masterpiece for his brother. Nate reappears and urges him to reconcile with their father. Dewey and his father wind up dueling with machetes; despite having trained years for this moment, his father cuts himself in half, forgives Dewey for Nate's death, tells him to be a better father, and dies. Dewey breaks down and destroys almost everything in his home. Dewey is approached by one of his illegitimate children and decides to reconnect with his many offspring. In 1992, a divorced Darlene returns to him. Finally realizing what is most important, Dewey regains his sense of smell and remarries her. In 2007, L'Chaim's son Dreidel informs Dewey of his popularity with young listeners through
rapper Lil' Nutzzak's
sampling of "Walk Hard". Dewey learns he is to receive a lifetime achievement award. They want him to sing a song at the ceremony, but Dewey is reluctant, fearing his old temptations. However, with his family's support, he reunites with his band and is finally able to create one great masterpiece, summing up his entire life with his final song, "Beautiful Ride", while also deciding against trying a drug,
viagra offered to him by Sam. A title card reveals that Dewey died three minutes after this final performance, which then also reads "Dewford Randolph Cox, 1936–2007". A
post-credits scene is a short black-and-white clip of "the actual Dewey Cox, April 16, 2002" (still played by Reilly). ==Cast==