HOLDING ON by Ernest Joselovitz. Directed by Alan O'Donovan; lighting by Tomm Tomlinson; acenery by Russell Metheny.

With Cliff Jewell, Jean Korey, Bevery Sheehan and Nelson Smith.

At the New Playwrights' Theatre through April 27.

Ernest Joselovitz's "Holding On" is, up to a point, an accurate and forceful evocation of the 1960s. The point comes, unfortunately, when characters first open their mouths, about 30 seconds into the play.

"What happened to right and wrong, good and bad?" asks Len, the young English teacher struggling to decide between the draft and flight to Canada. "Vietnam is a hall of mirrors," he says.

Two years later, Len returns from Vietnem to visit his college buddies in Minneapolis. But Frank -- who chose to evade the draft when Len chose not to -- doesn't even want to meet Len at the airport. "He should never have fought in that obscene war!" Frank exclaims.

Frank's meddling wife, Lois, meantime, is trying to play Cupid by reuniting Len with his ex-girlfriend, Ester. Len wants none of it. "You're different, I'm different," he tells Esther. "Can't you see that?" Frank and Lois "have their lives to lead and I have mine, and you have yours," he says.

"Holding On" -- at New Playwrights theather through April 27 -- is a four-character, one-set play. The set is fine. From its cinder-block-supported shelves to its vintage KLH portable stereo, designer Russel Metheny has brilliantly recaptured the look of the '60s off-campus living, and strains of Dylan and the Beatles make the feeling complete.

But those characters, Len, Frank, Lois and Esther speak a language best described as "dramatist's mumbo jumbo." Any resemblance to real persons, living or dead, is coincidential -- and fleeting.

Ernest Joselovitz, who wrote this play, is also the author of "Hagar's Children," one of the most successful productions in the NPT's eight-year history. It is hard to say just where Joselovitz went wrong with "Holding On." Perhaps the basic thematic territory -- the '60s, Vietnam and the draft -- has simply been explored to the hilt. If Joselovitz has something to add, "Holding On" never clarifies just what that something might be. And by the end of the play -- which has received only the crudest and most perfunctory production, scenery aside -- it would take an unnatural audience effort to care.

It is when Joselovitz gets furthest away from this theme and most deeply into his characters that "Holding On" comes to fitful life. There is something navively and likably audacious in the early phases of Len and Esther's love affair, told in flashback. While others are portraying the '60s as a time of liberated relationships -- witness the menage a trois of "A Small Circle of Friends" -- Joselovitz has the guts to depict a shy couple sharing a room for several nights before they share a bed.

But the skills that light up these passages would be better expended elsewhere. Whatever impelled Joselovitz to create Len, Esther, Frank and Lois and then build a play around them, his admirers must hope the condition is curable. "Holding On" isn't.