Packed in tight with a couple hundred (or thousand) dancing, sweating humans, there's just no way to avoid smelling one another. Admittedly, powerful body odor can be hard to bear, but that doesn't mean it's necessary to dip yourself in some substance designed to obliterate your body's self-producing scent. You're not a fox evading hunters — there's no need to throw the hounds off your trail.
It goes without saying (or it should) that most of the commercial perfumes and colognes are gruesome olfactory assault weapons that should be banned outright — not only because nearly a third of the population is sensitive to scented products worn by others, but also because many of them just plain smell gross [source: Caress and Steinemann].
And just because a scent is "natural" doesn't mean it's OK to broadcast it to the general public. Patchouli jumps to mind as the iconic hippie aroma of choice. Natural, yes; universally pleasant to inhale, no. The commandment for concerts and, in fact, all public spaces is: Bathe well, bring wet wipes and be free — scent-free.