Pedro Bell, whose mind-bending album covers for the band Funkadelic gave visual definition to its signature sound in the 1970s and ’80s, died on Tuesday in Evergreen Park, Ill., near Chicago. He was 69 .

George Clinton, the brains behind Funkadelic, announced his death on his Facebook page. Mr. Bell had been in poor health for many years.

Mr. Bell created his first cover for Funkadelic, the pioneering band that merged funk and psychedelic rock, in 1973. The album was “Cosmic Slop,” and it featured a topless woman, space imagery and mutants. Though Funkadelic and its sister act, Parliament, had been around for several years, Mr. Bell’s artwork and the liner notes he wrote under the name Sir Lleb (“Bell” spelled backward) helped define Funkadelic and its elaborate mythology.