Even though Saar's work embodies every kind of pain imaginable, from slavery and lynching to broken families and failed romance, it can be so brilliantly conceived and executed that laughter offers a momentary respite. The impatient viewer might miss the white-on-white KKK embroidered on the sheet hanging behind the ironing board in I'll Bend But I Will Not Break (1998) but not the infamous 1789 pattern of a middle passage slave ship or the way the old-fashioned flatiron is itself chained in place. Look long and deeply at any of Saar's pieces and you will see gleams of human individuality within the broad strokes of history.

Saar is a major 20th-century artist. Organized by the University of Michigan Art Museum, this, her first retrospective, clarifies her legacy as a pioneer of West Coast assemblage, which is distinct from the textbook East Coast forms exemplified by artists like Robert Rauschenberg. Joseph Cornell's boxes were an influence, but Saar does not require the cool New York mask of abstraction and encrypted symbolism. She was ahead of her time in her use of language and her frank presence in her work. Stitching together a torn photograph severing her image from her father's, she addresses personal and universal rifts.

"Extending the Frozen Moment" is centered on Saar's use of photographs. Sepia images record vintage family snapshots, beautiful young women, musicians and performers. Bittersweet (Bessie's Song), from 1973, is among the most lovely and haunting. PAFA's galleries are dimmed to protect fragile materials but that makes the bittersweet intimacy of Saar's work all the more palpable.