Bobby Eli, producer and lead guitarist of Philly studio band MFSB, has died. The news was confirmed by the Spinners’ official Instagram account — Eli famously played on recordings with the Spinners, among many other acts.

“Please join the #SpinnersFamily in celebrating the life of legendary #mfsb lead guitarist Bobby Eli, who transitioned today,” the Spinners’ account reads. “If the name isn’t familiar, believe us, his sound is. His guitar is a signature on so many classic #phillysoul hits, including many of our own. Celebrate his magnificent musical legacy by playing your favorite classic Philadelphia soul jams and be enthralled by one of the greatest guitarists in the realm of #soulmusic, and far beyond. He is an ascended master.”

Born Eli Tatarsky, Eli worked with numerous artists as a musician, arranger, composer, and producer. Some of them include the Jacksons, David Bowie, Jay-Z, Hall And Oates, Patti LaBelle, Elton John, B.B. King, Wilson Pickett, George Clinton, the Temptations, Curtis Mayfield, and Shaggy. He was also a session player for Gamble & Huff’s Philadelphia International label in the ’70s.

MFSB, standing for “Mother Father Sister Brother,” was a collective of more than 30 studio musicians based at Philadelphia’s Sigma Sound Studios. Their most successful single was “TSOP (The Sound of Philadelphia),” which was also the theme to Soul Train and is widely thought to have helped establish the disco sound. MFSB released seven studio albums, from 1973’s self-titled and Love Is The Message to 1980’s Mysteries Of The World.

In 2006, Eli opened Philadelphia recording studio the Grooveyard and mentored younger musicians.