Hey, cool, it don't get any easier than to perform for a large crowd. As someone else said above the hard part is the small groups. You can see everyone looking at you and that can get to you.

Also, performing in a group makes it easier to do. The largest crowd I've ever soloed in front of was about 200+. With the group I've sung to as many as 1000+. In the larger audiences it's easy for the individual faces to get lost in the wash of color and light.

You'll do fine. Have fun, be yourself and celebrate after the gig.