Massi married his wife Margie at age 18. Soon after, Massi served in the United States Army and was stationed in Japan. He and Margie eventually had three beautiful children together: Bobby, Patty and Nicky Jr.
Massi loved the guitar and was always passionate about music. In his early years as a musician he played with bands such as The Hollywood Playboys, The Variety Trio before he joined The Four Lovers in 1958, including some groups that featured future Four Lovers and Four Seasons members Frankie Valli and Tommy DeVito. After the group evolved into the Four Seasons, they performed such hits as “Sherry,” “Dawn (Go Away),” and “Rag Doll.”
As an original member of the group, Nicky was the bass guitarist, bass singer and vocal arranger. He was with the group for a total of five years and during this time contributed to over thirteen albums. Massi left the Four Seasons in 1965, and was replaced temporarily by Charles Calello who, in turn, was replaced by Joe Long.
Massi spent the rest of his life in West Orange with his family, but still remained very much involved with his musical passions by working locally in the recording industry managing and engineering groups such as The Baby Toys, The Victorians and The Carmel.