The pirating going on in Joseph Papp's production of Gilbert and Sullivan's "The Pirates of Penzance" at the National Theater is scene-stealing. Everyone -- principals, chorus, orchestra -- seems have have been given full liberty to plunder whatever the audience will yield, by any combination of audacity and ingenuity.

The result is a stage picture packed with visual tricks -- often so many of them at once that two or three members of the audience sitting next to one another can all be laughing simultaneously at different jokes. Here a member of the chorus is caught in the scaffolding of the set, there another is bullying a member of the orchestra, and way over there, a third has impaled himself on his own weapon. James Belushi, as the Pirate King, hardly has two minutes running -- and none still -- when he's not cutting, stabbing or slicing himself.

It's a more boisterous "Pirates" than the fans are used to seeing in this century, since Gilbert and Sullivan got themselves enshrined, but one entirely within their spirit. G&S specialized in topicality, and this production is topical -- culturally, rather than politically -- in Belushi's energetic anctics, Peter Noone's injection of a frisky modern sexiness into the fresh-faced role of Frederic, and Marsha Bagwell's adding extra swish to the sturdy comic part of Ruth, the nursemaid. Where it goes somewhat off is in the chorus of fair maidens, who are made up in a way that, in a Victorian context, can only suggest that they are moral outcasts, and some of whom overdo what might have been amusing gangliness to the point that they appear to be female impersonators. Also, Caroline Peyton, as Mabel, hit some wrong notes on opening night, and that is not as cute as hitting members of the orchestra.

THE PIRATES OF PENZANCE -- At the National through May 2.