STAYING ALIVE must be a struggle for legitimate theater in Boston; a trip to the Charles Playhouse will convince you of that. You walk past some of the city's most picturesquely seedy boarding houses to get there, and during intensely quiet moments on stage, boistrous music from the night club next door throbs through the walls. The management has decided to charge major league prices but can only provide pony league leg-room and ventilation.

What's happening on stage this month is worth a few bouts of brow-mopping in the second act, though. The Charles has dusted off one of the new, old chestnuts, John Osborne's Look Back in Anger, and pumped the play full of 20 times more life than it ever had in Humanities 7.

Director Jon Jory plays Osborne's violent love story straight. He seems a trifle bored with Osborne's speechy psychological explorations of the Porter's past, and he has schopped out the character of Colonel Redfern, apparently calculating that the scene which develops parallels between Jimmy Porter and his doddering father-in-law stifles the play's dramatic progression.

Skipping over some of the patient analysis in Osborne's script, Jory has chosen to rely entirely on a rapid flow of stage business to present his version of Porter. Jory keeps Marion Killinger pacing the stage with vicious energy, leaping onto tables, sprawling on the floor. He explains the man's anger with a series of visual and auditory irritations--the impassivity of Alison (Karen Grassle) at the ironing board, the obnoxious clang of evening bells, the black and white tedium of a litter of Sunday newspapers, constant courteous offers of a cup of tea.

Early in the first act, Killinger establishes the dumpy flat as his domain and Jory augments Osborne's complex stage directions with a few tricks of his own to keep it that way. For instance, the script calls for Porter to kick a cistern, then sit and play it like a Bongo in the second act. Jory has junked that and instead has Jimmy playing a complex jazz solo with plates and glasses on the bleak little tea table, as Alison announces that she's going out with her friend Helena. "That's not a direction," Porter replies in perfect syncopation, "that's an affliction."

And Helena is "an affliction," the Mayor Daley of the piece when it's presented fast and hard. She is the agent of the straight world, an actress and an emotional dilettante, prying with indecent interest into the Porter's peculiar menage and even playing a part or two in it. Osborne has written the role with a number of spendidly tinny or stilted lines ("Darling, why didn't you come to me?" "It won't be very pleasant, but I've made up my mind...") and Janet Sarno delivers them as though they are distantly remembered formulations from one of her many performances.

Jory's boldness has its perils, and once or twice he gets burned. With so much on Porter's stage command, the play sags whenever he is off. A long first scene of the second act, despite its deliniation of Helena's predatory habits, is a real albatross to this production.

The Charle's Look Back in Anger doesn't offer much in the way of thoughtful reinterpretation. It's better than that, alert to dramatic details all the way down to the hairstyles, exciting and a little angry itself.