AN AMERICAN TRAGEDY -- At the Arena through June 22.

When Theodore Dreiser called his novel "An American Tragedy," he didn't do it lightly. Just because American society now considers fornication more of a joke than a sin, that doesn't wipe out the point of his 1925 story about a young man who needs to get rid of one woman so he can marry another.

The point, then and now, was class mobility. Because Dreiser's Clyde Griffiths is an American, he knows that being born into a lower-class family needn't prevent him from rising, as an uncle has done, into comfort and fashion.

The tragedy is that he must change classes thoroughly when the great American opportunity presents itself, discarding all his previous connections, including, as it happens, a pregnant girlfriend who no longer fits in with his plans. But because it is America, she, too, has had a right to expect to rise -- to his level. And when he is tried for her murder, the official position, that class doesn't exist, obscures the true circumstances of the tragedy.

In Anthony Giardina's new play version at Arena Stage, directed by Michael Lessac, a heavy atmosphere of nostalgia suggests that this is a tragedy of naive days long ago. With tinkling music and characters who grin shyly and shuffle their shoulders, it has a certain mild sweetness, but none of the emotional impact of the novel, or of the film version.

No matter how long ago you saw the movie, you won't have forgotten the brooding sensuality of Montgomery Clift as a Clyde whom any rich girl would find fit, through personal qualifications alone, to be brought up to her status. And it wasn't any rich girl -- it was Elizabeth Taylor, representing all the temptations of beauty and luxury as the reward at the top. r

Arena's Clyde, played by Michael O'Keefe, is an awkward boy with nothing to say to girls of any class. The silliness of his being made to change clothes on stage continously and perform the currently obligatory male nude scene doesn't add to any social suavity he might have attempted.

Annalee Jeffries has some charm as the factory girl, but no suggestion of the exasperation she must produce in Clyde by clinging to him when he knows he can do better. And Marcia Hyde, as the society girl, is childish and giggly, with no suggestion of the power she can confer. Leslie Cass, as Clyde's mother, is obliged to do a parody of the religious hypocrite.

Everyone concerned would do well to remember that the passing of a few decades does not necessarily make tragedy cute.