Mark Stewart, the musician best-known for leading convulsive post-punkers the Pop Group, has died. Stewart’s Twitter reports that he died earlier today; no cause of death has been reported. Stewart was 62.

Mark Stewart grew up in Bristol, and that’s where he founded the Pop Group in 1977, when he was still a teenager. Stewart and his bandmates, who were friends from school, were inspired by the initial burst of punk rock, but they were also drawn to funk, dub, and free jazz, as well as explicitly political art and rhetoric. They released their debut single “She Is Beyond Good And Evil” in 1979.

The Pop Group were loud and discordant and sarcastic, and their whole approach was crucial to the development of post-punk. The Pop Group only released two albums before breaking up in 1981; their last performance was at a massive nuclear-disarmament protest in Trafalgar Square.

After the Pop Group’s breakup, Mark Stewart moved to London and worked with Adrian Sherwood’s On-U Sound label and became a member of the dub collective New Age Steppers. Stewart released a number of solo albums over the years, the most recent of which was 2022’s VS. In 2010, the Pop Group also reunited to play an All Tomorrow’s Parties festival in support of a series of reissues, and they remained active and released two more albums.