This afternoon in the Tent, Isaac Mizrahi staged what was possibly one of Bryant Park’s most theatrical runway shows. Mizrahi said the inspirations for the spring 2010 collection were the films of Fred Astaire — hence models walked up and down a staircase. This wasn’t as bad as it sounds for many girls, since some shoes only came with kitten heels. Some girls had to wear stilettos, however, which made one model’s stair climb in a floor-length ballgown especially scary to watch (she survived). A couple of lucky ladies were greeted mid-runway by an umbrella-wielding headset-wearing tech guy who walked them through a slanted shower of water “raining” from the ceiling. The theatrics were capped off with a golf cart, in which another tech guy drove a model onto the runway right before the finale. She got out and led the line of models backstage to close the show. Though if someone had sprained an ankle on those stairs, that little vehicle would have come in handy. The clothes and entire display — set to a live three-piece jazz band — was quite charming and humorous in a non-scary way. And the models and tech guys really earned their money this season. In a recession, that matters.