From sound recording’s earliest stages as a mass medium, when the music industry began stamping out flat records, to the breakthrough of MP3s and Internet-based music services, fans have been sharing music and pushing culture in unpredictable directions. Sound recordings allowed for the formation of rock and roll, a genre drawing from such a diverse range of musical styles that its impact on culture is unprecedented: Low culture challenged high-brow propriety, black culture spilled into white, southern culture infused the North, masculine and feminine stereotypes broke down, rural and urban styles came together, and artists mixed the sacred and the profane. Attempts to tame music were met by new affronts, including the British invasion, the growth of soul, and the political force of folk and psychedelic music. The gradual mainstreaming of rock led to the establishment of other culture-shaking genres, including punk, grunge, alternative, and hip-hop.

The battle over rock’s controversial aspects speaks to the heart of democratic expression. Nevertheless, rock and other popular recordings—like other art forms—also have a history of reproducing old stereotypes: limiting women’s access as performers, fostering racist or homophobic attitudes, and celebrating violence and misogyny.

Popular musical forms that test cultural boundaries face a dilemma: how to uphold a legacy of free expression while resisting giant companies bent on consolidating independents and maximizing profits. Since the 1950s, forms of rock music have been breaking boundaries, then becoming commercial, then reemerging as rebellious, and then repeating the pattern. The congressional payola hearings of 1959 and the Senate hearings of the mid-1980s triggered by Tipper Gore’s Parents Music Resource Center (which led to music advisory labels) are just two of the many attempts to rein in popular music, whereas the infamous antics of performers from Elvis Presley onward, the blunt lyrics of artists from rock and roll and rap, and the independent paths of the many garage bands and cult bands of the early rock-and-roll era through the present are among those actions that pushed popular music’s boundaries.

Still, this dynamic between popular music’s clever innovations and capitalism’s voracious appetite is crucial to sound recording’s constant innovation and mass appeal. Ironically, successful commerce requires periodic infusions of the diverse sounds that come from ethnic communities, backyard garages, dance parties, and neighborhood clubs. No matter how it is produced and distributed, popular music endures because it speaks to both individual and universal themes, from a teenager’s first romantic adventure to a nation’s outrage over social injustice. Music often reflects the personal or political anxieties of a society. It also breaks down artificial or hurtful barriers better than many government programs do. Despite its tribulations, music at its best continues to champion a democratic spirit. Writer and free-speech advocate Nat Hentoff addressed this issue in the 1970s when he wrote, “Popular music always speaks, among other things, of dreams—which change with the times.”27 The recording industry continues to capitalize on and spread those dreams globally, but in each generation, musicians and their fans keep imagining new ones.