Some day someone will probably invent an instrument that measures the energy that flows between a performer and an audience. And someday Liza Minnelli will probably blow its fuse.

To borrow a phrase from a song she sang last night at Merriweather Post Pavilion, Minnelli could "have bowed until she was sore at the waist." Backed by a 25-piece orchestra and dressed in a fiery red, beaded jumpsuit, Minnelli wowed the sell-out crowd with a show quite similar to her last engagement at the Kennedy Center in November 1979.

She was in magnificent voice throughout, whether wresting "New York, New York" away from Sinatra ("He sings it every time he opens his mouth," she joked), quietly reflecting on "The Man That Got Away," a song her mother first introduced years ago, or brazenly strutting across the stage in the fashion of Gypsy Rose Lee.

Joel Grey also brought a bit of Broadway to Columbia. Although occasionally cutesy, more often he was genuinely funny and entertaining, paying tribute to everyone from Al Jolson and George M. Cohan to Carmen Miranda and Jimmy Durante. The evening closed with Minnelli and Grey reunited in a couple of showstopping scenes from "Cabaret."