Whats the weirdest concert you ever attended?

I have to say this is only bought up by one particular concert I attended in 1970 in Birmingham England.
I went to see a German band called Faust. They had a bit of a reputation for being more weird than most, and that's saying something given other bands around at the time and had an underground following along with Henry Pig and Hatfield and the North.
So.... I was in row two and eagerly waiting for the show to start. The auditorium was completely dark except for the lights on the amps. At each side of the stage there was a big old 36" colour TV set and a pinball machine.

In due course, everyone assumed that the band came on stage as the light on the amps went off in sequence as if someone was walking past them. Then, eventually, odd sounds started emanating from where we assumed the band was. Still no lights. Then the TV's burst into life and were showing a different channel on either side of the stage. Still no sign of the band.
Next a guy walks on stage in just his underpants (1970's Y fronts)and starts playing the pinball machine. Every time he used the flipper the TV channel changed.

This was how the whole one and a half hours were spent until the guy on the pinball either got bored or the band got bored but he just walked off, the music stopped and the lights on the amps flickered again so we assumed that the band had left the stage.

During the course of the "concert", there was all sorts of aromas of illicit substances. To put the icing on the cake, about half way through, a woman in the front row turned round to me and said "would you hold this for me" offering a newly lighted special cigarette. After passing it to me she proceeded to turn back to the front, lean on the stage, have very quick very rough sex doggy fashion with someone I can only assume was her partner and then ask me for her joint back!

My head was really messed up for weeks and I'm still not sure if it was the concert or the side show which was to blame.
Todd Rundgren and Mojo Nixon tied for the most obscene and off the wall shows I have seen
Nothing really too weird, but I did see Elton John at the Hollywood Bowl in 1972, or '73. He was introduced by Linda Lovelace (of "Deep Throat" fame). Also, I went to a Bob Dylan concert at the Greek Theater (Berkeley) a couple of years ago. I waited until the last minute to enter because my ticket had a seat number and I wanted to avoid the early crowd. Once I got in, I looked for my seat number but learned that the words "General Admission" was code for standing room only, no seats. I guess everyone knew but me!
I'm a huge Miles Davis fan, but the only time I heard him live was a real disappointment. It was in the 70's during his "Jack Johnson" / "In a Silent Way" days. His side men played for awhile before Miles limped out (his foot was in a caste). Then he proceeds to play with his back to the audience for just about the entire time. Pretty short set too ... very uninspiring. I left thinking "what was wrong with that dude?"
Not a weird concert per se, but an unusual lineup was a Memorial Day weekend concert in the early 70's at The Joyous Lake, a small club in Woodstock, NY. Richie Havens played followed by the Charles Mingus Quintett and then Bonnie Raitt who was joined during her set by Paul Butterfield and Eric Andersen. Great show.