Loose Flange

I have a Canon T-70 & I just noticed the flange [I hope that term is correct, the chrome piece that fits to the lens] is a little loose. I have a pretty important gig tomorrow. Is there a way I can tighten this myself? & will this affect the photos?

A loose lens-mount flange might affect focus, depending on how loose, and in what manner.

I'm not familiar with the Canon you have, but many are attached with small screws that show on the face of the flange. Try carefully tightening them with a jeweler's screwdriver of the proper size. If that fails, use your backup camera. You do have a backup, right?

I have a back-up, but this one's my favorite. Thanks for the reply