According to his friends at the Alternative Tentacles record label, Willis was diagnosed with chronic myelogenous leukemia last year and underwent emergency surgery on June 2 to identify the source of, and to suppress, internal bleeding.

“It is not clear if this bleeding was related to his leukemia or not, and the exact cause of death is still unknown. Wesley had been recovering at a Hospice in Illinois, and since the surgery his health had deteriorated rapidly,” read a statement from the label.

Best known and loved for three-chord diatribes about super-heroes, everyday things and rock stars, Willis had a talent for being outrageous without being offensive or mean-spirited. Who else could get away with “I Wupped Batman’s Ass” and “Kris Kringle Was A Car Thief “?

His lyrics immortalized dozens of music personalities from Courtney Love to Rick Rubin, Steve Albini to Hootie & The Blowfish.

When he wasn’t addressing pop culture, he wrote and sang about the modern world in direct and often harsh terms. Willis penned songs about criminals and criminal justice, public transportation, religion and mental illness with piercing clarity. And asses. Willis liked the word ass. A lot.

He recorded well over 50 albums – all free of any and all artifice. There was nothing phoney about Willis or his music, ever. When he sang “Rock over London! Rock over Chicago!,” it wasn’t a cliche, it was a command.

Alternative Tentacles said Wesley Willis Greatest Hits Vol. 3 had already been scheduled for release this October at the time of his death.