Now, you can't expect to look as amazing as you possibly can if you don't have enough time. You have to lower your expectations. You can still look pretty good, though, despite your time limitations.
Slap on a dress that you have worn before for performances and one that you know will be the proper length. Part of being a performer is having a go-to outfit for times like this. My outfit is a black dress that goes to my knees, with a dark red cardigan and a black belt.
Brush out your hair and put in some anti-frizz creme to tame it. You don't have time to style it, so don't worry about volume or curls. Straight will do. The anti-frizz creme will calm it down so it doesn't look like you just got out of bed. If you want, you can twist back your bangs and pin them up with a bobby pin; I didn't have time for it.
There are 3 essential make-up tools that you should use at the minimum: foundation, mascara, and lipstick/gloss. I used powder foundation, did my mascara and put on my lipstick in 5 minutes. Quick and easy.
Pop on those heels and you are out the door!
You may not look as amazing as you normally would in these situations, but you will still look like you belong on the stage!
Hope that this helped! What are your quick tricks to getting ready in a rush?