To the extent that August Wilson's plays are about validating community -- perhaps, in a larger sense, even creating it -- Saturday's festivities announcing the arrival of the Center's new home felt on target.

The block of Liberty alongside the striking, largely complete structure was closed for a street fair, with vendors of food, art and crafts, and at one end a stage for live music and other performance. If the crowd was multiethnic, the vibe was Afrocentric -- entirely appropriate for a Center for African American Culture.

Of course, the Center's most concrete legacy will be the building itself. At 60,000 square feet of space for exhibits, performances, education and more, it cost nearly $40 million. It's not quite done: Informal guided group tours watched their step, tromped through plaster dust and consulted posted artists' renderings to get a better idea of the finished product (set for unveiling in September).

But what's there is encouraging. A spacious second-floor gallery for temporary exhibits offered a slide-show preview of the first, one that will recreate rooms from an historic house in the Hill District. There'll also be a studio space for rehearsals and informal performances (complete with sprung floor for dancers). In the education center (just an open space for now), we watched storyteller Amir Rashidd tell African folk tales, aimed mostly at kids, with a wisdom and panache one could imagine the late Wilson himself admiring. And the big theater space -- complete with several hundred seats and a balcony -- was already humming with a full day's slate of local performers of all ages, from gospel singers to hip-hop dancers. (The stage will be formally christened June 11, with a concert by Me'Shell Ndegeocello.)

But the best part of architect Allison Williams' design, I thought, was the windows. Most of the structure's two-story Liberty Avenue face is plate glass, and from the second-floor studio and education center you got a sweeping view of the sunlit street teeming with visitors. Clever notches in the walls provided other viewing angles on the rest of Downtown and even on a wooded hillside of the Hill District, which of course is Wilson's old neighborhood.

All that natural light will surely help the Center in its quest for LEED certification as an environmentally sensitive building. But if the building's very existence, especially in such a prominent location, is a long-overdue validation for African-American culture in Pittsburgh, the effect of the windows in particular is transformative. Just as in Wilson's plays, where a backyard or a living room or the interior of a diner is made to seem the focal point of an entire world, so the Center's windows join the building's inside to its outside. They definitely make you feel part of a community.