Is it inappropriate to be kilted at Midnight Mass Christmas eve?

I will be singing in the choir loft with my choir. We won't be down front, so the concern about being a distraction or an attention hog really doesn't fly.

If you think it's okay, what would one wear if one didn't have an Argylle? I do have a PC and waistcoat, but is that too formal? Blue blazer, shirt and tie, maybe?