Concerts from the past

Whilst driving around in the car this weekend, listening to the crowd's enthusiasm for Tangerine Dream's Cherokee Lane (live on Encore) and remembering similar on [The Name of This Band Is Talking Heads](http://en.wikipedia.org/wiki/The_Name_of_This_Band_Is_Talking_Heads), I got to wondering about all of the great concerts that I've missed.

When I get around to fixing my time machine, what are the top twenty concerts that I absolutely have to see and hear in person?