Terminology question: "Cocktail attire requested"

A friend and I got a deal to attend a magic show here in LA, and one of the notes in the description says, "Cocktail attire requested."

What does this mean? The venue is a pretty ritzy hotel (Beverly Wilshire Hotel) at night with a small audience, probably fewer than 60 audience members. I'm assuming it's more formal than typical "business casual" dress shirt and slacks, which probably means dark suit and tie. Unfortunately, the only suits I have are.....well, crap, to put it lightly.

I do own a pretty nice BB tux that I got recently for a wedding. Can I dress it down for something like this? No tie, with a plain white shirt or even a colored/patterned/dark shirt?

Quote:

Originally Posted by unbelragazzo 

Get a decent suit. This won't be the last time you'll be needing it.

I plan to, but not on such short notice. All the online MTM stores seem to take about a month to make one.

Quote:

Originally Posted by unbelragazzo 

Get a decent suit. This won't be the last time you'll be needing it.

I plan to, but not at such short notice. I was thinking of either propersuit.com or blacklapel.com (leaning towards the former), but all of the online MTM stuff seems to take a month and a half.