Seattle Center’s latest manifesto for the future is “The Next 50.” The idea is, a half-century after our ’62 World’s Fair (which brought Elvis, the Monorail, etc.), that the old grounds should again be revitalized with yet another remodel of the armory, a new Dale Chihuly gift shop (er, sorry, museum), an improved stadium, and so forth. But a funny thing has happened around the center, much of it without direct city investment. First came Paul Allen’s EMP in 2000. Bill Gates recently planted his new foundation next door. Amazon has brought thousands of tech workers to nearby SLU; and the Mercer Street redo will make walking and biking connections, at least, that much easier. Also, despite the real-estate bust, new apartments continue to rise around the 74-acre campus and its precious open space. Today, Seattle Center launches a 50th-anniversary historical exhibition, organized by MOHAI, called Celebrating Century 21 (in the old Northwest Craft Center). Additionally, the half-centennial party includes music, food, a reunion of the Almost Live! crew (John Keister, Nancy Guppy, etc.), readings by Tom Skerritt and others from Paula Becker and Alan J. Stein’s recent fair history The Future Remembered, public art works, a new dance piece (The Chair Spectacle) from choreographer Pat Graney, an appearance by the Rat City Rollergirls, and sundry family activities. BRIAN MILLER

Sat., April 21, 10 a.m.-6 p.m., 2012