Wayne Kramer, the co-founder, lead guitarist, and vocalist of the iconic Detroit proto-punk outfit MC5, has died. The news was shared on Kramer and MC5’s official social media pages. A cause of death was not disclosed. Kramer was 75 years old.

Kramer and his bandmates got their start a young age, forming the Bounty Hunters while students at Lincoln Park High School in the suburbs of Detroit in 1963. Kramer and Fred “Sonic” Smith played guitar; Rob Tyner sang; Michael Davis was on bass; and Dennis “Machine Gun” Thompson was the drummer. Not long after formation, the group adopted the new name of the Motor City Five, later shortened to MC5.

“The MC5 used to play everywhere: school cafetoriums, dances, record hops, bars, clubs, outdoors, indoors, sideways, upside down, you name it, we were there,” Kramer has said of his band’s early days. “When you love to play music, it doesn’t matter where you play it. You just establish a good band and put your 10,000 hours in playing your asses off anywhere-anyway you can.”

MC5 released their first two songs—a cover of “I Can Only Give You Everything” and their own “One of the Guys”—in 1967 through the Detroit garage rock label AMG Records. Following its release, Kramer and his bandmates continued to garner attention through touring and their radical left-wing politics, encouraged by their manager and White Panther Party co-founder John Sinclair.

“Politics is obviously where the power to change the country is, but I don’t mean John Sinclair politics, youth politics,” Kramer told Rolling Stone in 1972. “Sinclair was talking about all this alternative shit, and one of his big schemes was the tribal system where there would be little tribes in each city and then all the tribes from the different cities would get together for a youth-council-tribal-powwow, and that’s just a whole bunch of hokey shit to me, man. Because politics is where the power is, man, and if you want to change this shit, man, you’ve got to put somebody in office that’s got the ideas and the philosophy that you entertain, you know.”

Under Sinclair’s guidance, MC5 released the live album Kick Out the Jams in 1969. For its second album, 1970’s Back in the USA, the group went to the studio and recorded with producer and eventual Bruce Springsteen manager Jon Landau. MC5 released just one more album, 1971’s High Time, before disbanding in 1972.

From 1975 to 1978, Kramer served time in a Lexington, Kentucky, federal prison for selling what he once described to NPR as “a big pile of cocaine” to undercover officials. While in Kentucky, Kramer played in a prison band with Red Rodney, a jazz trumpeter who’d played with Charlie Parker. His experiences in prison informed his 2014 free jazz album Lexington, which doubled as the score to a documentary about the prison where he served his time, The Narcotics Farm.

“In the end, it may have saved my life, because I was traveling in a very dangerous world in Detroit, at the peak of my drinking and drugging,” Kramer told Rolling Stone in 2014 of his incarceration. “But I don’t think prison helped me. Prison time doesn’t help anyone, the way we approach punishment in America. There might be a way, if the entire system was shifted to restoration: what we can do to help people who have made bad decisions and broken the social contract.”

Following his release from prison, Kramer began his solo career in earnest in the 1990s, releasing his debut, The Hard Stuff, in 1995. He later released a memoir of the same name in 2018.

Beyond his recording career, Kramer launched the nonprofit Jail Guitar Doors with his wife and manager, Margaret Saadi Kramer, and Billy Bragg in the mid-2000s. The organization, in its own words, is dedicated to “providing musical instruments and mentorship to help rehabilitate individuals experiencing incarceration through the transformative power of music.”

Kramer, joined by Kim Thayil, Brendan Canty, Dug Pinnick, and Marcus Durant, revived MC5 in 2018 for a tour celebrating the 50th anniversary of Kick Out the Jams. In 2022, Kramer brought MC5 back again for a tour with singer Brad Brooks, drummer Stephen Perkins, bassist Vicki Randle, and guitarist Stevie Salas. He also said he was working on a new album, featuring production by Bob Ezrin and some percussion from Dennis “Machine Gun” Thompson.

This article was originally published on Friday, February 2, at 4:47 p.m. Eastern. It was last updated on on February 2 at 5:40 p.m. Eastern.