Sgt. Pepper's Lonely Hearts Club Band is the eighth studio album by the English rock band the Beatles. Released on 26 May 1967, Sgt. Pepper is regarded by musicologists as an early concept album that advanced the roles of sound composition, extended form, psychedelic imagery, record sleeves, and the producer in popular music. The album had an immediate cross-generational impact and was associated with numerous touchstones of the era's youth culture, such as fashion, drugs, mysticism, and a sense of optimism and empowerment. Critics lauded the album for its innovations in songwriting, production and graphic design, for bridging a cultural divide between popular music and high art, and for reflecting the interests of contemporary youth and the counterculture.

The Beatles were an English rock band formed in Liverpool in 1960, comprising John Lennon, Paul McCartney, George Harrison and Ringo Starr. They are regarded as the most influential band of all time and were integral to the development of 1960s counterculture and the recognition of popular music as an art form. Rooted in skiffle, beat and 1950s rock 'n' roll, their sound incorporated elements of classical music and traditional pop in innovative ways. The band also explored music styles ranging from folk and Indian music to psychedelia and hard rock. As pioneers in recording, songwriting and artistic presentation, the Beatles revolutionized many aspects of the music industry and were often publicized as leaders of the era's youth and sociocultural movements.