Is there a dress code for concerts at the MGM Grand Garden Arena?

My sister and I are going to the MGM in a few weeks to see Lady Gaga, and I want to wear caution tape shorts, with caution tape and telephone cords wrapped around me but without a shirt. Would I be against some rules doing this? I was there before, and I saw a few people without shirts on, but no one actually walking in without them. So I'm lost. -_-