What transpires within the American Center’s new walls also raises the stakes far above the American pop music that seems to saturate every public place in France. The private, nonprofit American Center was founded in 1931 for cultural exchange – and as a place for the American colony to social-ize during Prohibition without hanging out in cafes drinking wine. Since the ’60s, the center has been a flash point for contemporary American art, dance and music, with workshops, visiting artists and performances. When the center outgrew its headquarters in Montparnasse, the City of Paris encouraged a move to Bercy, an old neighborhood of wine warehouses and railroad tracks.

Bercy – with the new National Library going up nearby – is supposed to become the next hip neighborhood in Paris, but so far it’s pretty dead. To respect the streetscape, Gehry’s $21 million, eight-story building looks calmly out on the Rue de Bercy, but on the other side, facing a park, it explodes with the jumble of jutting angles and curves that are the Los Angeles architect’s hallmark. Down one wall tumbles a cascade of angled glass panes. Enter under a swooping zinc awning (““under a ballerina’s skirt,’’ Gehry says) and you come into a lobby animated by balconies, staircases and spilling light – a plaza where people can bump into each other going to lunch or to rehearse in a dance studio. The lively, intricate interior includes a 400-seat theater, two film/sound studios, galleries and 26 apartments for artists.

What was new for Gehry was to make his idiosyncratic shapes mostly of limestone, with zinc roofs, like classic parisien architecture. ““It was my fantasy of France,’’ says Gehry. ““I love the cleavage of the roofs. The Hotel de Ville is my favorite, the ultimate cleavage. That inspired me. And I love the stone of Paris. It’s like the stucco of L.A.''

Some L.A. flavor extends to ““Pure Beauty,’’ the opening exhibition of young L.A. artists whose subject is – sacrebleu! – pop culture. Bill Viola has also done a haunt-ing video installation. A committee, drawn from U.S. cultural hot spots like Minneapolis’s Walker Art Center, is now shaping the center’s programs. Next year ““African-American Artists in Paris, 1945-60,’’ put together by the Studio Museum in Harlem, will open at the center, with programs on black musicians and writers of the period.

If the center provokes cultural debate, it begins with the building itself. Some French critics think Gehry was too polite, that his building isn’t wild enough. That’s the rap he takes for paying attention to the urban context: he’s made a building that fits in Paris, not California. Yet the American Center is quintessentially American – energetic, open, optimistic. In a city with so little great contemporary architecture – witness most of Francois Mitterrand’s grands projets – this stunning building is a milestone in Franco-American cultural relations.