Big Dee Irwin first came to prominence in the Pastels, a group that sang doo wop during the 1950s. The New York City native, whose real name was Defosca Erwin (sometimes spelled Difosco Ervin), joined forces with three other young men to form the group in 1954 when all were stationed at a U.S. Air Force base in Greenland. Lead singer Irwin joined a talent competition held for servicemen, along with baritone Jimmy Willingham, first tenor Richard Travis, and second tenor Tony Thomas. When all four singers received orders that took them to Washington, D.C., Irwin and the Pastels began to entertain at nightspots that catered to servicemen, as well as at functions hosted by the USO. In 1957, after receiving a warm and encouraging response for their performance in an annual Air Force competition called Tops in Blue that was staged on the grounds of Mitchell Air Force Base in New York, Irwin and the others set out to land a recording contract. That summer they almost landed a deal with Central Records. Some sources say that Irwin and the Pastels actually did snag a long-term contract, but the group never made a record for the label. Instead, the Pastels landed on the doorstep of Hull Records. The four singers belted out "Been So Long," which Irwin had penned. With a few changes and some fine-tuning of the arrangement, the song was put out late in 1957 by Mascot, a division of Hull. "My One and Only Dream" landed on the flip side.
Irwin received his military discharge papers the following year. By that time, his fellow group members also had been released from duty, and "Been So Long" was doing extremely well on the charts. It reached the Top Five in R&B and crossed over to pop, where it landed at number 24. Irwin and the others embarked on a tour of the southern states of the U.S., including stops in Florida and Louisiana. By then, Chess Records had reissued the record on the Argo label. Irwin led the group through a succession of live shows around the country. Several were staged at the Apollo Theater in Harlem, where they shared the stage with the Deltones, Little Willie John, and others. At the Uptown Theater in Philly, they were part of the Georgie Woods Show along with Chuck Berry, the Chantels, Little Joe & the Thrillers, among others. They also appeared in the lineup for concerts staged by rock & roll showman Alan Freed across the U.S., alongside such acts as Buddy Holly & the Crickets, Jerry Lee Lewis, Screamin' Jay Hawkins, the Diamonds, and Frankie Lymon. Irwin sang lead on the Pastels' next record, "You Don't Love Me Anymore," which was issued in 1958, as well as "So Far Away" six months later. Irwin and the Pastels returned to the Apollo for a week's worth of gigs that same year, the first on Halloween night. When the Pastels fell apart the following year, Irwin remained in New York City to try for a solo career. Things started to click for him in 1963 when he recorded "Swinging on a Star" and headed to the U.K. for an extended tour. The refurbished Bing Crosby hit from 19 years earlier also featured vocals from Little Eva. She again joined the heavyset singer on "Happy Being Fat." Irwin continued to record as a solo artist for the remainder of the decade. In addition, he penned numbers for Isaac Hayes, Ray Charles, Bobby Womack, and the Hollies, who included his "What Kind of Boy" on their first full-length release. By the mid-'70s, he had reinvented himself as DiFosco and was recording disco for Roxbury. Heart failure claimed his life in 1995.