That is really great! I think the dress code depends on location, location, location! Also the price of the tickets also gives a little clue too. But, anyways, I believe that for something really formal あなた will want to if your a man invest in renting a tux または a really nice suit. If your a woman a long dress should do. あなた can pick the color if あなた want but classy Colors（色） like red, black, etc. are the best. If it is not as formal for boys just wear a nice button up シャツ with some nice pants. If your a girl あなた could pick the same color dress and\or style but a little shorter. Well i hope あなた have fun at your concert!!
