If the Bauhaus and the modernist architecture that ensued had never happened, Edward P. Bass said as he gestured out from the mezzanine over an entrance foyer graced with pilasters, fluted columns and a frescoed dome: "This is what you would get."

What you get, with last week's opening of the Nancy Lee and Perry R. Bass Performance Hall here, is by far the most traditional concert hall built in the United States in more than 65 years. The movement to repeal modernism, having spread from homes to baseball parks, has now penetrated the world of high culture.Bass Hall aims to be an updated Carnegie Hall, a marble and Texas limestone embodiment of the 18th- and 19th-century masterpieces to be performed there. It also crowns the revival of a downtown that became a victim of the car culture two decades ago. Count the two 48-foot-tall herald angels on the building's facade as the city's largest civic boosters.

While the concert hall refuses to be bound by formulas, the downtown area's recovery, under Bass' primary guidance, closely follows the precepts of two prophets of urban design, Jane Jacobs and William H. Whyte.

Urban planners hail Fort Worth as proof that no downtown is beyond rescue. "Among people who are looking for new ways to bring life to existing cities," said Fred Koetter, dean of the Yale School of Architecture, "it could stand as a model." Fort Worth's success has inspired open envy especially in Dallas, a city long used to regarding its smaller neighbor (population not even half a million) as laughably mired in stockyard muck.

Working in Fort Worth's favor was an ample stock of turn-of-the-century rehab-ready brick buildings and the ability of the Bass family, one of the nation's wealthiest, to buy about 40 blocks. The Bass brothers - Sid, Edward, Robert, and Lee - turned a family oil fortune worth tens of millions into a diversified empire worth billions.

The Basses named their redevelopment district Sundance Square because it once provided hideouts and illicit pleasures for outlaws such as Butch Cassidy and the Sundance Kid. Even on weeknights, the brick sidewalks here are crowded with office workers hanging around for dinner or a movie and tourists hopping between nightclubs and stores. Some Fort Worth residents, however, say their downtown has become a bland, sanitary amusement park, brought to them by the family that, as investors, helped turn around the Walt Disney Co.

The local symphony, opera, and ballet, as well as the Van Cliburn International Piano Competition finals, have been using a convention center auditorium, since it has taken three of the four Bass brothers more than two decades to develop the alternative.

Ed Bass, a pioneer resident of downtown, began considering what private money alone, and not only his family's, could do. To design Bass Hall - named for the Bass brothers' parents, who donated the land - he chose David M. Schwarz.

Ed Bass wanted an architect who could recapture the era before performing arts centers became aloof outdoor sculptures. That era ended in the early 1930s with the completion of Severance Hall in Cleveland, which Schwarz is now expanding, and the War Memorial Opera House in San Francisco.

Bass Hall "is designed to fit into the urban fabric as much as Carnegie," Bass said as he began his tour.

Befitting a practical-minded town that grew up as a cattle-kingdom capital, the hall abounds with refreshment counters, donor plaques, and restrooms. For 2,056 seats, the Bass Hall men's rooms have 38 stalls; the women's, 64. Carnegie Hall, with 2,804 seats, has 40 and 47. Bass boasts of keeping to a $67 million budget. Some economies are evident in the blank side and rear facades and the Erector-set loudspeaker towers at the corners of the stage.

(Bass is best known for his $150 million Biosphere II experiment in ecological self-sufficiency.)

Features borrowed from Carnegie Hall include tiers shaped like horseshoes and boxes with anterooms, which have been sold to Fort Worth's wealthy like sports-arena luxury suites.

But Bass Hall is not slavishly imitative or backward looking. Polished and brushed aluminum and steel, even some cables more commonly used in airplanes, are featured in the lighting and railings. A spotlight booth is all glass and exposed steel beams.

Unlike Carnegie, Bass Hall has to present opera, ballet, rock concerts, and Broadway shows as well as classical music. The solution, courtesy of Schwarz and Jaffe Holden Scarbrough Acoustics of Norwalk, Conn., is a hall eager to adapt. The push of a few buttons, for example, drapes the walls in heavy velour to absorb amplified sound.

The hall's Disneyesque opening managed to pack Carol Burnett, Frederica von Stade, Fort Worth's own Van Cliburn, and all the city's major performing arts groups into a program ranging from Verdi and Puccini to "Deep in the Heart of Texas."