Act One (Vivian Beaumont Theater, Lincoln Center, closes June 15). James Lapine’s thrillingly well-staged dramatic adaptation of Moss Hart’s theatrical autobiography, in which Tony Shalhoub plays both George S. Kaufman (Hart’s collaborator and mentor) and Hart in middle age, has the open-hearted impact of a melodrama, one that has the advantage of being true. His was an old-fashioned American-dream-come-true tale, and it doesn’t embarrass Mr. Lapine in the least to dish it up on a pageant-like scale reminiscent of the spectacular stage version of Nicholas Nickleby. You’ll cheer–and cry (TT).