Oliver Herring would like your attention. The German-born, Oxford-educated, New Yorkbased artist would like you to perform a few small favors during his daylong participatory performance piece Task. If you show up, hell assign you some seemingly mundane errand within the Rem Koolhaas librarynothing dangerous or embarrassing, we promise!that will lead to interaction with others being similarly dispatched with written directives. (If this sounds a little like a scavenger hunt, it is, but also with the DNA of Duchamps instruction art, plus kinship to the Fluxus movement and the Situationists.) This will be Herrings fifth such collaborative performanceand he remains the performer, the locus of the piece, not you. Citizen assistants can sign up in advance through the Web sites of On the Boards and the Frye Art Museum. After a 2006 performance at the Hirshhorn Museum in Washington, D.C., the artist wrote to his minions, Besides all the exuberance, there was plenty of seriousness and mission on display. But perhaps we have so many opportunities to feel anger and frustration and express it in so many ways, that an outlet to tap into something positive was needed far more. Not exactly the words of an angry, confrontational avant-gardist. More like the happy hub of a communitarian enterprise. Which, even if the volunteer roster is filled, you can observe without cost, angst, or obligation. Seattle Central Library, 1000 Fourth Ave., 386-4636, www.spl.org. Free. 10 a.m.5:30 p.m.