NEW YORK (AP) ' Imagine you're in the audience at, say, "Swan Lake," and the ballerinas you've been watching suddenly swoop over to your seat, envelop you with their wings and spirit you onstage to flutter along en pointe.

Not gonna happen ' except maybe in a vivid dream after a late-night viewing of "Black Swan." But at Alvin Ailey, where the very vocal audi.....