Dexter Wansel, a forefather of alternative R&B and the gifted songwriter/producer of hits such as Patti LaBelle’s “If Only You Knew,” died Sunday in Philadelphia of undisclosed causes. He was 75.

A Philadelphia native born Aug. 22, 1950, keyboardist Wansel was an errand boy for the local Uptown Theater while growing up. Following a stint in the Army, he began working at the city’s famed Sigma Sound Studios, where he gained the attention of Kenneth Gamble and Leon Huff, the Grammy-winning co-founders of pioneering soul label Philadelphia International Records. As a recording artist for the label — beginning with his influential 1976 debut album Life on Mars in addition to wearing multiple hats in-house as a writer, arranger, composer, conductor, producer and A&R director into the ‘80s — Wansel earned a reputation as one of the vital craftsmen in developing the inimitable “Sound of Philadelphia.”

In a joint statement sent to Billboard, Gamble & Huff commented, “Dexter Wansel brought a new age sound to our record label in the 1970s and ‘80s, arranging and producing hits for many of our artists such as The Jacksons, The Jones Girls, Jean Carne and MFSB Orchestra, and including hits for himself. Dexter’s synthesizer and symphonic keyboard sounds were iconic.”

Encompassing vibrant fusions of R&B, funk, jazz and futurist/electronic grooves coupled with lavish orchestrations, those sounds were the hallmark of Life on Mars and the three additional albums that Wansel released via Philadelphia International. The projects include 1977’s What the World Is Coming To, 1978’s Voyager and 1979’s Time Is Slipping Away.

Wansel stayed just as busy behind the scenes at the label during the late ‘70s and into the ‘80s. He teamed with in-house lyricist Cynthia Biggs for a fruitful run that reaped songs such as LaBelle’s No. 1 R&B single “If Only You Knew,” The Jones Girls’ “Nights Over Egypt,” The Stylistics’ “Hurry Up This Way Again,” Grover Washington Jr.’s “The Best Is Yet to Come” featuring Patti LaBelle and Phyllis Hyman’s “Living All Alone.”

Wansel was also a producer on Lou Rawls’ 1977 album Unmistakably Lou, for which the singer won a Grammy for best male R&B vocal performance. Wansel’s work has also been sampled by various hip-hop artists, including Kendrick Lamar, Wiz Khalifa, Lil Kim, Drake and J. Cole. Over these later years, Wansel released other solo projects, among them: Captured (1986), Digital Groove World (2004) and The Story of the Flight Crew to Mars (2021).

Added Gamble & Huff, “Dexter’s prolific songwriting with his long-time writing partner Cynthia Biggs  – who worked with Teddy Pendergrass and others — made them one of the most sought-after writing teams in our publishing company.  Most importantly, Dexter was our dear friend, protegé and great contributor to the Sound of Philadelphia. We send our sincere condolences to his wife Judy and family.”

Wansel is survived by his Grammy-nominated songwriter/producer son Andrew “Pop” Wansel of Pop & Oak. The younger Wansel’s credits include projects by Usher, Kehlani and Alessia Cara.

A statement from the Wansel family states, “We wish to express our gratitude for the outpouring of condolences we are receiving for our loved one, Grammy winner and one of the architects of the Sound of Philadelphia, Dexter Wansel. He’s at peace now.”

Memorial details will be announced at a later date.