Bob Crewe, the songwriter and producer who was to all intents and purposes the unseen fifth member of the Four Seasons, co-writing many of their greatest hits, including "Sherry," "Big Girls Don't Cry," "Walk Like a Man" and "Rag Doll," died on Sept. 11, 2014. He was 83.

Mr. Crewe, whose impact on America's hit parade was felt from the 1950s through the '70s, penned or produced infectious songs for everyone from Roberta Flack to Labelle. But it was his connection to the New Jersey pop group the Four Seasons that brought him his greatest notoriety. His frequent co-writer was Four Seasons member Bob Gaudio, with Gaudio handling the music and Crewe the lyrics. Their compositions also included such Four Seasons staples as "Let's Hang On" and "Dawn."

All these and more received a new dose of exposure in 2005 when they became the basis of the score for the Broadway hit Jersey Boys. Earlier this year, the musical was made into a movie by Clint Eastwood.

In the play, Crewe is also a character, depicted as a fairly openly gay man whose flamboyant personality is completely at odds with the up-from-the-streets, tough-guy temperament of the Four Seasons. Like the members of the group, he was born in New Jersey, in Newark, on Nov. 12, 1930, and raised in Belleville. He gravitated toward music and art at an early ager, and attended the Parsons School of Design. He won a recording contract as a singer, but scored his first big success as a writer, co-writing, with Frank Slay, The Rays' doo-wop hit "Silhouettes" in 1957.

Other familiar songs either written or produced by Mr. Crewe included "Jenny Take a Ride" and "Devil With a Blue Dress On" (recorded by Mitch Ryder and the Detroit Wheels), "Jean" and "Good Morning, Starshine" (Oliver) and "Lady Marmalade," a number one hit for Labelle in 1974. When Frankie Valli left the Four Seasons to go solo, Mr. Crewe co-wrote for him the hits "Can't Take My Eyes Off of You," "Swearin' to God" and "My Eyes Adored You."

In 1966, he formed a group of musicians that he called The Bob Crewe Generation. They had a modest instrumental hit with "Music to Watch Girls By."

Bob Crewe was inducted into the Songwriters Hall of Fame in 1985.