About halfway through The Threepenny Opera last night, Susan Channing walked out onto Aggassiz stage to sing. She plays Jenny--Lotte Lenya's old part. She is supposed to be a tough whore, and she she looks like a kewpie doll. She has a sweet, smooth voice that certainly doesn't suggest here upbringing. She isn't wearing very much either.

So what does she do? Does she ugly up her voice, play the sex queen, scatter knowing winks? Not a bit of it. She just stands there and sings--throwing in a few minute gestures. And as the song gets grizzlier she sings softer and softer, until she's almost whispering--about piles of dead bodies. It was chilling.

I don't know where Mrs. Channing got the nerve to put on that sort of an exhibition, but she couldn't have played it any other way. And in fact, a good part of the cast kept doing things I wouldn't have suspected they'd be up to. Actors with no apparent sense of timing turned out to be marching to a distant crucial drum. Some sooty cripple who would have been booed down at a PTA benefit stuck up her face and said her little pice at, peek-a-boo, just the moment a touch of farce fit in.

There was a sly gutsiness about this whole production that gave me the feeling my responses were being tampered with. The actors kept ducking out from under the characterizations I tried to pin on them, and shrugging off my sympathy. I'm no expert on Brecht, but I understand that's what's supposed to happen. If it isn't, director Timothy Mayer has certainly produced something intriguing.

And Mayer must get much of the credit. David Sloss did a superb job with the music, true, and Lewis H. Smith's costumes went a long way toward making the show the confident spectacle it was. But Mayer is the one who put it together and made it work. When he had talent to use, he used it. When he didn't, well, he got something out of the actor anyway. He knows what theatre is about. You could give him a flashlight and two deaf mutes and he'd make money with them.

This production wasn't just another series of already mastered gimmicks. Often I've found myself watching plays at Harvard and saying, ah yes, that trick with the voice, I saw that before in--, or that wonderful way of walking, no one can do that like she can. But Three-penny was a world of its own. I got interested in the delapidated characters, even when they crossed me up. At the curtain call I found it hard to shake the impression that they were half-imaginary people.

As for the troupe, my favorites after Mrs. Channing were Johanna Madden (Mrs. Peachum), Jane Gratwick (Polly), Virginia Manack (Lucy), and William Hodes in the relatively minor part of Crookfinger Jake. It may be, however, that I was less impressed by Dean Gitter (Macheath) because he never gave me any reason to worry about him. He was obviously in command whenever he was on stage, and with a weaker actor in the part, the play would have limped. I didn't tune in on Arthur Friedman (Peachum) until the last act, and if I saw the play again, I'd probably like him better.

I could find things wrong with this production. That's what I'm here for I suppose. But after the first half hour, last night, I stopped wanting to. And I still don't.