Sad news albeit he's been in poor health for a while. Saw Pere Ubu play The Modern Dance all the way through along with the early singles at a gig a few years ago, bloody brilliant.
One of those extraordinary bands I missed first time around, only encountered them in the last couple of years having read Will Sergeant's autobiography where he said they were a big influence on Echo and the Bunnymen's guitar sound. Seems like they influenced many, Pixies are mentioned a lot which you can hear in The Modern Dance while 'Heart of Darkness' from 1975 sounds very Joy Division.
Saw them at the Kentish Town and Country Club probably about 35 years ago now. Unique, energetic, entertaining, and influential as you say.
I saw him live twice. Once with Pere Ubu on the Tenement Year tour at the Leadmill. Think that was 86. Saw him about 10 years ago with Rocket from the Tombs. He was in a chair by then. I'm a huge Pere Ubu fan and very sorry to hear of his passing. A true maverick.