"A work of art, architecture, whatever it is, needs time to finally make a judgement as to whether it's right or not," says I.M. Pei in First Person Singular (1997), Peter Rosen's fine documentary about the architect. It is a cruel irony that after 30 years, what many consider Pei's greatest work, the East Building (right) of the National Gallery in Washington, D.C., has gone seriously wrong.