So I've been reading Kraftwerk - Man, Machine and Music. The book mentions a pretty scandalous concert that Tangerine Dream and Nico put on in 1974. The venue was the Reims cathedral, and the scandal was such that the Catholic church decided they had to reconsecrate the place. The book didn't go into detail, but I imagined some clergyman perched in a balcony beneath clerestory windows, frozen in terrified indignation as the wild, cosmic reverberations of TD and Nico assaulted his sense of propriety. A quick Google search revealed the church's primary beef to be a little more on corporeal side of things; after the crowd dispersed, there was a fair amount of pee on the floor.
I haven't listened to the concert itself (which you can download here for free), but this youtubed portion of Nico's performance is cool. It must have been a pretty celestial experience for the members of the audience not preoccupied with incontinence issues.