What to wear to a concert tonight? Help

[user1467042399]

I'm going to see Beyoncé tonight it's a stadium concert and it's raining at the minute.
I want to look nice but at the same time it will be wet and probably cold by 10pm
I've bought a waterproof Mac from primark as I will need a coat but What underneath?
Will people be dressed up?

Minidress, gilet and wellies.

My experience of outdoor concerts is it varies from jeans and t shirt to some who glam up. I tend to stick to the former tbh. And I'd take a hoodie and mac to keep warm too.