By the time of his death, at 37, in 1973, the show’s final descent into lugubrious eulogy — “He finished six years of grammar school in four years and got a scholarship medal besides,” Nina says — has swamped its early buoyancy with platitudes. Yet Groff is still swimming, right to the end. Dismayed as I was to endure so much else, I have to admit he’s giving one of Broadway’s best performances. So who’s sorry now?