Francesco Stephen Castelluccio (born May 3, 1934), known professionally as Frankie Valli, is an American singer, known as the frontman of the Four Seasons beginning in 1960. He is known for his unusually powerful lead falsetto voice. Valli, Tommy DeVito, Nick Massi and Bob Gaudio – the original members of the Four Seasons – were inducted into the Rock and Roll Hall of Fame in 1990 and the Vocal Group Hall of Fame in 1999.