During research for an article on the 30th anniversary of Pompilli’s death, researcher Chris Gardner uncovered documents that showed Pompilli was actually born in 1924, not 1926 as had commonly been believed (like Haley, Pompilli also shaved two years off his age).

Pompilli was skilled at playing both saxophone and clarinet, and spent the beginning of his career playing in jazz bands. In 1953 he was with the Ralph Marterie Orchestra. That orchestra coincidentally scored a hit with a cover version of Haley’s “Crazy Man, Crazy”, though research by Haley historian Chris Gardner found no evidence that Pompilli performed on that recording.

Pompilli was invited to join the Comets in September 1955, after Haley’s previous sax player, Joey Ambrose quit along with two other Comets to form The Jodimars. According to Haley, the young horn player had a dislike for rock and roll musicians, but he nonetheless accepted the offer. Ambrose gave Pompilli a crash course in the Haley style of saxophone playing, and he also learned the stage antics pioneered by Ambrose and bass player Marshall Lytle, including playing the sax while lying flat on his back and jumping all over the bass player. (Lytle also left for the Jodimars and was replaced by Al Rex.)

Within a few months of joining The Comets, Pompilli had become the band’s most visible member (aside from Haley himself), becoming the focus of “Rudy’s Rock”, a show-stopping instrumental co-written by Pompilli and Haley that debuted in the 1956 film Rock Around the Clock. When released as a single, “Rudy’s Rock” reached #34 on the Billboard singles chart and #38 on the Cashbox Top Singles list, spending 4 weeks on that chart, and making it the first instrumental record of the rock and roll era to chart. Other acclaimed, but less commercially successful instrumentals followed, most notably “Calling All Comets” which was performed in the band’s next film, 1957’s Don’t Knock the Rock.

He was named Sax Player of the Year by Down Beat magazine in 1957.

In 1958, Rudy’s cousin, Al Pompilli, joined the Comets for a year, playing bass after the departure of Al Rex.

Rudy Pompilli co-wrote the hit “Week End” with Franny Beecher and Billy Williamson, which reached No. 35 on the Billboard pop chart when released as a single in 1958 as by The Kingsmen on East West Records, East West 115. He also co-wrote the B-side, “Better Believe It”, with Johnny Grande and Ralph Jones. A follow-up single was released on East West, “Conga Rock”, written by drummer Ralph Jones, backed with “The Catwalk”, written by Franny Beecher and Billy Williamson, as East West 120. Pompelli composed the hit “Florida Twist” with Anthony Caruso, which reached No. 3 as an Orfeon 45 on the Mexican pop singles chart in 1962 based on the Billboard Hits of the World chart. “Florida Twist” has since become a party standard in Latin America and has been covered by many artists in rock and roll, Tex-Mex and other genres.

He co-wrote “Week End” with Franny Beecher and Billy Williamson and the B side, “Better Believe It”, with Johnny Grande and Ralph Jones. He co-wrote “Rudy’s Rock” with Bill Haley and “Calling All Comets” with Bill Haley and Milt Gabler. He co-wrote “Hey Then, There Now” with Ralph Jones. He wrote “Florida Twist” with Anthony Caruso. He also co-wrote “Lean Jean”. His other compositions were “China Twist”, “Happy Twist”, “Tacos de Twist”, and “Twist del Dia” in 1962.

Pompilli died from lung cancer on February 5, 1976, in Philadelphia. His death affected Haley deeply. After fulfilling touring commitments for the year with a replacement sax player, at the end of 1976 Haley announced his retirement from performing and moved full-time to Mexico. Haley would return to touring and recording in 1979 and would dedicate a part of every show to Pompilli’s memory with a performance of “Rudy’s Rock”.

In 2012, Pompilli was inducted as a member of the Comets into the Rock and Roll Hall of Fame by a special committee, aimed at correcting the previous mistake of not inducting the band with Bill Haley in 1987.