It will be hot, whether it is an indoor venue or an outdoor one. So don’t weigh yourself down with thick, bulky clothing. Also don’t wear anything too expensive because it may get ruined in the crowd. Nothing beats jeans and a t-shirt for concert wear. For shoes, depend on boots. Flip-flops are not an option because the crowd will get rowdy (hello … it is a Mindless Behavior concert!) and may step on your slippers.
If jeans and a T-shirt sound a little too casual, halter tops are great too, ladies. Also try peasant shirts that are cool, comfy and perfect for the potentially suffocating environment inside of a concert hall!
Whatever you do, avoid wearing shirts from the band as they may make you seem a bit obsessed. Remember: be cool!