Four young men from the wrong side of the tracks in New Jersey come together to form the iconic 1960s rock group The Four Seasons. The story of their trials and triumphs is told through the eyes of the band members, each with his own perspective on the journey. Frankie Valli, the group's lead singer with a distinctive falsetto voice, Tommy DeVito, the charming yet troubled lead guitarist, Bob Gaudio, a gifted songwriter and keyboardist, and Nick Massi, the bassist who strives to keep peace, navigate the complexities of the music industry while dealing with personal issues and the challenges of mob ties.

As the group achieves fame, the pressures and temptations of life on the road take a toll on their friendship and the band itself. The personal story behind their public success emphasizes the strong brotherhood that formed between them, with their shared experiences reinforcing their bond. The climb to the top is marked by hit songs that earn them fans across the world, but internal conflict and external pressures threaten to tear the group apart. Each member grapples with his own ambitions and demons, all contributing to the fractious but resilient nature of their relationship.