Sir George Henry Martin was an English record producer, arranger, composer, conductor, and musician. He was commonly referred to as the "fifth Beatle" because of his extensive involvement in each of the Beatles' original albums. Martin's formal musical expertise and interest in novel recording practices facilitated the group's rudimentary musical education and desire for new musical sounds to record. Most of their orchestral and string arrangements were written by Martin, and he played piano or keyboards on a number of their records. Their collaborations resulted in popular, highly acclaimed records with innovative sounds, such as the 1967 album Sgt. Pepper's Lonely Hearts Club Band—the first rock album to win a Grammy Award for Album of the Year.

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.