I attended the year The Producers swept the awards. While most men were in tuxes and most women wore gowns, there were definitely men in suits and women in cocktail dresses. If you're up in one of the balconies, I wouldn't think a tux would be required.
"It does me no injury for my neighbour to say there are 20 gods or no god. It neither picks my pocket, nor breaks my leg."
-- Thomas Jefferson