Two or three years ago, when we had a season here of 1930s musicals (it was the year before we had all the 1940s revivals), someone must have wished that shows like that were still being written. Now we've got it -- a brand-new musical comedy that's just as silly as anything that would give you an attack of nostalgic hilarity, or hilarious nostalgia, if were a period piece.

"Oh, Brother!," at the Eisenhower Theater, is supposed to be a modern version, with some liberties, of Shakespeare's "The Comedy of Errors," which, in its day, was a modern version of Plautus' "Menaechmi" and "Amphitryon," with which Shakespeare certainly took liberties.

This time it's set in Iran, and concerns the romantic involvement of various separated twins with the daughters of the Ayatollah. "Revolution's the solution" the armed chorus sings on an oil-well-studded beach. One of the minor effects of Iran's behavior to America was that it made laughing at other peoples respectable again -- there is hardly a '30s musical that doesn't contain a comic routine based on bigotry of one kind or another -- and no protests are expected about the Ayatollah's daughter's repeatedly calling him a medieval cuckoo.

Funny people dash about chasing one another, the dirty puns are so awful that the characters all say how awful they are, and an oversize moon arises at love-song time. That song goes something like: Bangle-laden OPEC maiden Your lips exude An Arab crude That drives me simply wild. I hope I find You nonaligned In a Third World made for two."

Eddie Cantor himself couldn't have put it worse.

All this is performed with as much commotion as possible, and the contagious enthusiasm of, among others, Judy Kaye and Mary Mastrantonio as the daughters and Harry Groener and Alan Weeks as the western halves of the two sets of twins. The author, Donald Driver, rhymes "destiny" with "manifest to me," and stages everything as if it were rush hour.

Every outrage is forgivable, except the length. It's half an hour too long -- as is every new musical that opens here before going on to Broadway in a shortened form. Can't we all chip in and buy one of those giant timers for backstage at the Kennedy Center and set it for two hours?

OH, BROTHER! -- At the Eisenhower Theater through October 24.