The Four Seasons is an American vocal quartet formed in 1960 in Newark, New Jersey. Since 1970, they have also been known at times as Frankie Valli and the Four Seasons. The band evolved out of a previous band called The Four Lovers, with Frankie Valli as the lead singer, Bob Gaudio on keyboards and tenor vocals, Tommy DeVito on lead guitar and baritone vocals, and Nick Massi on bass guitar and bass vocals. On nearly all of their 1960s hits, they were credited as The 4 Seasons. The band had two distinct lineups that achieved widespread success: the original featuring Valli, Gaudio, DeVito, and Massi that recorded hits throughout the 1960s, and a 1970s quintet consisting of Valli, Lee Shapiro, Gerry Polci, Don Ciccone and John Paiva, with Gaudio and Long providing studio support.

Francesco Stephen Castelluccio, better known by his stage name Frankie Valli, is an American singer, best known as the frontman of the Four Seasons beginning in 1960. He is known for his unusually powerful lead falsetto voice.