Not only were there thousands of longhairs at Ozzfest in Somerset, Wisconsin, I also saw a bumper sticker for sale that said, "Just say no to haircuts," with a picture red circle-slash over a pair scissors. My husband doesn't allow bumper stickers on the car, so I didn't get one, but I'd definitely buy a shirt like that if I saw one.
There have been a number of longhairs at Summerfest in Milwaukee, Wisconsin, too... all manner of styles-- braids, ponytails, loose, mullets-- and all manner of lengths and colors. It's interesting to see certain style variances the seem to sometimes correspond with the genres of music offered.
At Ozzfest, the undercut seemed to predominate; an increasingly popular variation is the undercut with the hair in many skinny braids.

Kind of like this?
Interesting...
I've never seen that particular sub-style, but it's really interesting!
At Summerfest, there were a lot of mullets when Alan Jackson came, and more loose styles for the metal-type groups. I did see a rainbow-colored mohawk that then extended down the back-- the most amazing thing I've ever seen!
A newer style with the youth I noticed had the hair about 3-4" around the head, gathered in pointy little cone-shaped things. (Like a longer spike-type haircut that was popular in the mid-eighties.
Yesterday, though, most guys had their hair in a ponytail due to the sweltering, humid heat.