The Four Seasons Leader is Frankie Valli, an American singer and actor. He is best known as the frontman of the Four Seasons, a popular rock and roll band from the 1960s. Valli's powerful falsetto voice and distinctive style helped make the group one of the most successful musical acts of the era. Valli has had numerous solo hits, including 'CAN't Take My Eyes Off You' and 'My Eyes Adored You'. He continues to tour and perform today.