IS THERE ANYTHING GOING ON UPSTAIRS?, at the American Theater Company. Denise La Grassa is a true hybrid, part jazzy cabaret singer, part trippy performance artist, part witty stand-up comic. And her current collagelike show–a combination of monologues, scenes, and songs–reflects her eclecticism and energy. There’s something thrilling about watching her leap from one character to another like some Chicago version of Heather Woodbury, playing a panoply of urbanites with equal aplomb. And the girl can sing.

If only she had better material. La Grassa writes her own, and she depends way too much on her considerable charm (and the kindness of her audiences) to get her through the show. Few of her characters are fleshed-out, and those that are fully developed aren’t onstage long enough for us to get to know them. And too many of the show’s 20 or so vignettes and tiny monologues feel pointless or inconsequential: there are times when La Grassa changes locations and characters so quickly it’s as if she were aimlessly flipping channels–and finding nothing on.

–Jack Helbig