I have no idea. The Rolling Stones played in Austin a few years ago at Zilker Park. The stage was reported to be 91 feet tall. I remember you could see it sticking up above the trees from the freeway. That one required a crane truck and took a few days to put up and take down. Up until then, I hadn't seen such a large stage before. I think around 70,000 people saw the concert. I live about 5 miles from the park, and could hear the low rumble of the music. Then after the concert they had a fireworks display, and I could see it.
You can see pictures of the stage during the concert at this Flickr account:
http://www.flickr.com/photos/oldaust...n/photostream/
More here:
http://www.flickr.com/photos/cwriter111/277276341/