The Beatles were an English rock band formed in Liverpool in 1960. They became the most commercially successful and critically acclaimed act in the history of popular music. Their best-known lineup consisted of John Lennon, Paul McCartney, George Harrison, and Ringo Starr. Rooted in skiffle and 1950s rock and roll, they later utilised several genres, ranging from pop ballads to psychedelic rock, often incorporating classical and other elements in innovative ways. In the early 1960s, their enormous popularity first emerged as "Beatlemania", but as their songwriting grew in sophistication, they came to be perceived by many fans and cultural observers as an embodiment of the ideals shared by the era's sociocultural revolutions.