Going to a music festival without sunscreen is just about as wise as going without water. Don't be that person who gets taken to the hospital with second-degree burns. There are plenty of great spray-on sunscreens with wide-spectrum coverage and sweat-resistant formulas. Try Hawaiian Tropic Island Sport SPF 30 ($11). It's completely clear, and because it's dispensed by a spray, you're less likely to miss any spots.