In 1982, British heavy metal rock band, Spinal Tap, arrives in New York City on a promotional tour for Smell the Glove, their first album in several years, and documentarian Marty DiBergi films them. In an interview with Marty, founding band members and childhood friends, Nigel Tufnel and David St. Hubbins, describe their formation in 1964. Although they first called themselves The Originals, the musicians changed their name to The New Originals to distinguish themselves from another band with the same name, but later became The Thamesmen. Nigel, David and bass player Derek Smalls explain the strange deaths of their past drummers. At the tour’s opening night party, Spinal Tap is greeted by hostess Bobbi Flekman, an “Artist Relations” manager at Polymer Records, and she introduces them to the label’s president, Sir Denis Eton-Hogg. The next day, as Spinal Tap is chauffeured through the city, David demands to know when Smell the Glove will be released, but their manager, Ian Faith, dodges the question by mentioning a New York Times review. Ian claims that Polymer is focusing its distribution efforts in Philadelphia, Pennsylvania, instead of New York, because it is a “rock ‘n roll town.” At Fidelity Hall in Philadelphia, the band performs “Big Bottom” to a cheering crowd. Later, as the band attends a recording industry convention in Atlanta, Georgia, Ian again evades Spinal Tap’s inquiries about their album. Ian adds that the cancellation of their show in Boston, Massachusetts, is negligible because “it’s not a big college town.” Hosting another cocktail party for the band, Bobbi tells Ian that Polymer is offended by Spinal Tap’s record cover design, which portrays a naked woman on all fours, chained to a leash, with a glove shoved in her face. After a phone call from Eton-Hogg, Ian informs the band that the release of Smell the Glove has been cancelled because of its “sexist” cover. Bewildered, Nigel questions “what’s wrong with being sexy,” but Bobbi argues that Polymer has no leverage with big retail chains such as Sears and Kmart, who are boycotting the album, because Spinal Tap’s past records were not successful. Fielding Spinal Tap’s protests, Bobbi promises to work out a compromise with Eton-Hogg. At their next performance, Nigel complains to Ian about the snack food backstage. During the show, Nigel leans backwards playing a solo in the song “Hell Hole” and a roadie helps him to his feet. In an interview with Marty, Nigel shows the filmmaker his guitar collection and custom Marshall amplifiers that surpass the maximum volume of “ten” and “go to eleven.” At a hotel in Memphis, Tennessee, Spinal Tap discovers their reservations have been downgraded and, in the lobby, they are snubbed by fellow rocker, Duke Fame, who attracts the attention of girls David presumes are Spinal Tap fans. When Duke’s promoter brushes them off, Spinal Tap complains that the rocker’s album cover is just as exploitative as theirs, but Ian explains it is permissible because Duke is tied up as the “victim,” not the girls. Ian then announces that the Memphis show is cancelled because of “lack of advertising funds.” When Marty interviews Ian about the declining popularity of Spinal Tap, the manager argues that their “appeal is becoming more selective.” On a phone call with his girlfriend, Jeanine Pettibone, David conveys that more shows have been called off, but he is delighted to learn she will join them for the remainder of the tour. Nigel, however, is displeased by the news and becomes further downtrodden when a radio disc jockey plays a Thamesmen song and announces that Spinal Tap is in the “’Where are they now?’ file.” In an interview, Spinal Tap discusses their 1967 hit single, “Listen to the Flower People” and the spontaneous combustion of their drummer. During a sound check at Shank Hall in Milwaukee, Wisconsin, Jeanine surprises David with her arrival and Ian presents the band with long-awaited, pressed copies of Smell the Glove. Displeased that the cover is devoid of an image, David complains that its color is depressing and Nigel says that it is “none more black,” but Ian encourages the musicians to persevere. However, Spinal Tap’s next show is besieged with absurd technical problems. In a Chicago, Illinois, Holiday Inn hotel room, the band meets the Midwestern promoter for Polymer, Artie Fufkin, but when he takes them to a record store album-signing event, no one attends. Later, at the Xanadu Star Theater in Cleveland, Ohio, the band gets lost backstage. At a diner, the band tells Ian that the black album cover has been a curse and, in an effort to improve their image, David presents Jeanine’s drawings for Zodiac sign costumes. Disparaging her ideas, Nigel uses a napkin to design a Stonehenge stage prop and Ian says he will have it constructed. Before the Austin, Texas, show, however, Ian realizes Nigel’s drawing specified a height of eighteen inches instead of eighteen feet, but he compensates for the discrepancy by hiring two little people to dance around the Stonehenge prop and the musicians are outraged. After the show, David berates Ian for turning their performance into a farce; and, when he suggests that Jeanine co-manage the band, Ian quits. During a recording session, Nigel blames David’s poor concentration on Jeanine and after the band arrives in Seattle, Washington, Nigel becomes more enraged when he learns she booked their concert at Lindbergh Air Force base. There, Lt. Hookstratten tells Spinal Tap that the base is celebrating an “at ease weekend,” but the audience is disturbed by the band’s performance of “Sex Farm.” When Nigel’s wireless amplifier picks up a radio feed, he throws his guitar down and storms off stage. Later, as Jeanine looks for Nigel’s replacement, David tells Marty that he will never again play with his lifelong friend. Spinal Tap arrives at Themeland Amusement Park in Stockton, California, to discover they are second billed to a puppet show and decide to improvise a set under the name “Jazz Odyssey.” At the end-of-the-tour party, David refuses to admit Spinal Tap is finished, but Derek suggests that they focus on different projects. Before the last show, Nigel appears backstage with a message from Ian. “Sex Farm” has hit the charts in Japan and Ian suggests the band re-form for a Japanese tour. Although David shrugs him off, he later invites Nigel to join him onstage while the band performs “Tonight I’m Gonna Rock It Tonight.” Despite radio interference on his amplifier, Nigel plays his trademark solo. At Kobe Hall in Tokyo, Japan, Spinal Tap performs for a sold-out audience with a new drummer.