Pink Floyd still sounded as good as I've ever heard them though.

As for AC-DC not being asked to play. I don't think the bands were asked. It was the bands that asked if they could play. And because of the speed at which the concert was planned and booked etc bands such as Status Quo couldn't make it due to other arrangements.
I was dissapointed though that Paul Mccartny didn't sing Mull of Kintyre just to help everyone on their way home.
