William “Poogie” Hart, vocalist and founding member of the Philadelphia soul group the Delfonics, has died, TMZ and The Philadelphia Inquirer report. Hart was taken to Temple University Hospital in Philadelphia after experiencing difficulty breathing and died Thursday night due to complications from surgery, according to the reports. He was 77.

The Delfonics grew out of Hart’s time in Philadelphia with the Orphonics, a band he founded with his brother, Wilbert “Wil” Hart, and high school friends Randy Cain and Richie Daniels. William Hart was introduced to legendary writer-producer Thom Bell by Del-Vikings singer and eventual Delfonics manager Stan Watson. Bell would go on to arrange and produce their 1966 debut single as the Delfonics, “He Don’t Really Love You”  b/w “Without You,” as well as other early recordings including 1967’s “You’ve Been Untrue” and 1968’s “La-La (Means I Love You).”

“La-La (Means I Love You)” peaked at No. 5 on the Billboard pop charts, and was featured prominently on the soundtrack for Quentin Tarantino’s 1997 film Jackie Brown. The film’s soundtrack also included the Delfonics’ 1969 hit “Didn’t I (Blow Your Mind This Time),” which peaked No. 10 on the Billboard pop charts in 1970 and helped the band win the 1971 Grammy award for Best R&B Performance by a Duo or Group. The latter single was featured on the band’s 1970 self-titled album, which also made an appearance on the charts, peaking at No. 61 on the Billboard 200 albums chart.

While the Delfonics officially broke up in 1975, the band’s members continued to release music. Major Harris notably broke on to the Billboard Hot 100 in 1974 with his hit “Love Won’t Let Me Wait,” while William Hart continued to perform with core Delfonics members—including Major Harris and Randy Cain—into the 1980s.

The band’s legacy took on new life in the 1990s, as they became a key source for samples and collaborative material. Their 1968 song “Ready or Not Here I Come (Can’t Hide From Love)” was sampled by the Fugees on their 1996 single “Ready or Not.” Missy Elliott also sampled the 1968 standout on her track “Sock It 2 Me” with Chicago rapper Da Brat. In 2013, producer Adrian Younge teamed up with William Hart for the collaborative album Adrian Younge Presents the Delfonics, which paired the Delphonics’ classic sound with a 2010s hip-hop edge.

Following Willam Hart’s death, Younge shared a statement on his verified social media accounts mourning the loss of his friend and collaborator. “You taught me so much and gave so much to the world of music,” he wrote. “The master singer…the master writer…the man that created songs that changed the world. You are missed brotha. Love you man.”