Center Stage.(Lincoln Center for the Performing Arts)

Alice Tully Hall, and the Juilliard School complex of which it is a part, were the last elements of Lincoln Center to be built, and when they opened, in 1969, they seemed like an ambitious attempt to bring cutting-edge brutalism to the place. That's probably why so many architecture critics liked them and so many other people didn't. Amid the tepid classicism of so much of Lincoln Center, Juilliard stood out as something totally nineteen-sixties, all cantilevers and boxy geometries. Granted, it was covered in travertine, to match its genteel neighbors, but that served only to make the building seem ill at ease, like a wrestler dressed in a Sunday suit.

The building was a misfit in other ways, too. Alice Tully Hall, Lincoln Center's main venue for chamber music and recitals, was supposed to be its most conspicuous public element, but the entrance was half hidden behind a stairway that led up to a bleak, windswept plaza. It was also separated from the street by a small, virtually useless triangular plaza, a result of the insistence by the architects, Pietro Belluschi and Eduardo Catalano, on a rectangular building, even though the site, facing the diagonal of Broadway, was a trapezoid. If you were going to Juilliard instead of to Alice Tully, the front door was even harder to find--off the plaza, one level above the street.

So there is a certain justice in the way that this structure, designed with apparent disdain for the traditionalism of its neighbors, has turned out to be the first part of Lincoln Center to be radically rebuilt. (I'm not counting Avery Fisher Hall, the Philharmonic's acoustically challenged concert auditorium, whose interior has been redone four times, but whose exterior remains intact.) In February, Alice Tully will reopen as, for all intents and purposes, an entirely new hall. Large sections of the surrounding Juilliard building have been renovated, and almost nothing about approaching, entering, and being inside the complex is the way it was. The architects, Diller Scofidio + Renfro, have stretched Juilliard's rigid box all the way to Broadway, giving the building a shape that, at last, reflects the outline of the site. They have covered the new Broadway side of the building in glass--including a spectacular dance studio on the second floor which seems to float over the entrance. And they created a new front door by cutting a huge diagonal swath out of the southeast corner of the building. From some angles, it looks as if a giant had wrenched the building out of its foundation by lifting up the corner. When you get close to the door, the corner seems to loom over you, like an enormous triangular canopy. Forty years after Alice Tully Hall opened, it finally has an entrance that you notice.

Architects sometimes talk of design elements as "moves," as if they were playing a game of chess, and when dealing with problematic older buildings the chess analogy is apt. You are more likely to succeed if you craft a strategy consisting of a lot of carefully considered small moves, not one big one. That's one reason for the failure of Frank Gehry's plan, a few years back, to solve Lincoln Center's problems by putting a gargantuan glass dome over the main plaza. Move by move, you have to take your cues from the architecture that is already there, but you can't let the older building dictate everything, either. Liz Diller, Ric Scofidio, and Charles Renfro, along with their associate architects, the firm of FXFowle, have figured out the balance. They joust with Belluschi's architecture, but they never try to kill off the old structure. They manage to be bold and subtle at the same time, making a dull building exciting without warping its identity completely.

Belluschi wouldn't have liked the renovation, an affront to his doctrinaire modernism, but almost every change has made this building better--both more alive and more functional. From Sixty-fifth Street, it looks almost the same, and where the architects have extended the south side to the corner of Broadway they even copy Belluschi's travertine facade--perhaps as a gesture of homage, but also more likely because nothing else would make sense there. Yet from Broadway you see only the new material, and the building becomes another thing entirely, a vibrant composition of glass and metal that looks, and feels, strikingly new. Previously, once you found the door, you entered a cramped vestibule and then walked down several steps to a low-ceilinged, carpeted lobby that felt like a basement. Now, when you pass through the corner entrance, you find yourself in a vast glass-enclosed space--it includes most of the ...