In Jenny Perlin's Washing--a brief, silent 16-millimeter film the color of urine-stained newsprint--a view of the Brooklyn Bridge through a window is erratically obscured by a woman's hand wiping the glass with a cloth. Her obsessive gesture never cleans the window, but as you focus on what's beyond her hand you suddenly realize that you could have seen the Twin Towers from here. And then there they are, muted but perceptible. If they'd been more easily seen, more distinct, I might have written the piece off as a well-made sympathy card, but Perlin's compostitions and timing are remarkable. She also proves a master manipulator in a three-channel video projection titled Sight Reading. According to the press release, three professional pianists were given a tricky Schumann work to sight-read, and Perlin edited the footage so that a screen goes dark whenever someone makes a mistake. It feels like a competition--the pianists are shown side by side on the three screens, and they start at the same time. Things get ugly as the screens keep going dark and the music stops, a punishment for the performers and for us. Then you notice that sometimes things that sound or look like mistakes have been left in--the woman on the right starts and stops several times, but the screen doesn't go black. And you notice that since we don't see the mistakes we don't know what they were or even if they were mistakes. What's fair? Perlin seems to be asking us to consider. Who's to judge? Gallery 400, University of Illinois at Chicago, 1240 W. Harrison, through June 12. Hours are 10 to 5 Tuesday through Friday and noon to 5 Saturday; 312-996-6114.