Pedro Bell, the Chicago visual artist behind many iconic Funkadelic and George Clinton album covers, has died. He was 69 years old, according to a report by The New York Times. The news was shared by George Clinton and Bootsy Collins.

In his 2014 memoir, Clinton said the band began receiving letters from Bell around 1972. “He doodled these intricate, wild worlds, filled with crazy hypersexual characters and strange slogans,” Clinton wrote. Clinton and Bell began speaking over the phone, and from their conversations, Bell created his first cover for Funkadelic: 1973’s Cosmic Slop. “When he sent us his interpretation, I was blown away,” Clinton wrote. “It included pimps and hos, some of which were drawn as aliens with little worms coming out of them. It was nightmarish and funny and beautiful, a perfect fit for the music we were making.”

Bell went on to create many of Funkadelic’s best known album covers, including 1974’s Standing on the Verge of Getting It On, 1975’s Let’s Take It to the Stage, and 1978’s One Nation Under a Groove. He also worked on a string of George Clinton’s solo covers, including 1982’s Computer Games. Bell’s work has been displayed in museums and galleries internationally.

Bell was profiled by The Chicago Sun-Times in 2009. The piece depicted the artist attempting to sell original versions of his iconic artwork while living in poverty and struggling with poor health. Bernie Worrell performed at a 2009 benefit concert to help raise money for Bell.