The Beatles were an English rock band formed in Liverpool in 1960. With members John Lennon, Paul McCartney, George Harrison and Ringo Starr, they became widely regarded as the foremost and most influential music band in history. Rooted in skiffle, beat and 1950s rock and roll, the Beatles later experimented with several genres, ranging from pop ballads and Indian music to psychedelia and hard rock, often incorporating classical elements and unconventional recording techniques in innovative ways. In 1963, their enormous popularity first emerged as "Beatlemania"; as the group's music grew in sophistication, led by primary songwriters Lennon and McCartney, they came to be perceived as an embodiment of the ideals shared by the counterculture of the 1960s. The Beatles built their reputation playing clubs in Liverpool and Hamburg over a three-year period from 1960, with Stuart Sutcliffe initially serving as bass player. The core trio of Lennon, McCartney and Harrison, together since 1958, went through a succession of drummers, including Pete Best, before asking Starr to join them in 1962. Manager Brian Epstein moulded them into a professional act, and producer George Martin guided and developed their recordings, greatly expanding their domestic success after their first hit, "Love Me Do", in late 1962. As their popularity grew into "Beatlesmania", they toured extensively around the world until 1966, when they played their last public performance, an impromptu gig at Candlestick Park in San Francisco. During their studio years, the Beatles produced what many consider to be some of the finest pop music ever recorded. Although their initial musical style was rooted in 1950s rock and roll and skiffle, they later incorporated elements of classical music and experimented with pop balladry and Indian music. They also explored genre-spanning ideas such as drug culture and social change. The Beatles' influence on popular culture is incalculable; their break-up in 1970 was a worldwide sensation. Their songs have been covered by hundreds of artists and have been featured in films and television commercials. The Beatles are the best-selling band in history, with estimated sales of over 600 million records worldwide. They have had more number-one albums on the UK charts (15) and held the record for most weeks at number one (174) than any other artist.