When the folks at the Whitney Museum decided to call the sound-art portion of their massive American Century retrospective "I Am Sitting in a Room," they were both wryly acknowledging their own presentation of a hundred years of American sonic innovation (which was mostly people sitting in a gallery listening to recordings) and paying homage to New Hampshire-born sound arts pioneer Alvin Lucier, whose landmark 1969 piece I Am Sitting in a Room introduced into modern composition a new awareness of acoustics and language. To perform the piece, Lucier would record himself reciting a simple, prosaic passage describing what he was doing, then play it back into the room and rerecord it and play it back, again and again, until the words blurred into the distortion and echo caused by the resonant properties of the room. By the end, his recitation would be reduced to an eerie, layered, semiorganic pause and pulse. Lucier has further explored acoustics, duration, tuning, gestural sound, and the actions of sound waves in works ranging from Bird and Person Dyning (a 1975 piece that combines binaural microphone feedback and birdcalls) and Theme (a 1994 piece in which a reading of a John Ashbery poem is recorded by microphones placed inside a seashell, a milk bottle, a vase, and an ostrich eggshell). He has also written chamber works, solo pieces, and works for orchestra; presented sound installations in the U.S., Japan, and Europe; and recently collaborated on a theater presentation, Skin, Meat, Bone, with playwright Robert Wilson. For this rare Chicago performance, part of Experimental Sound Studio's Outer Ear festival, Lucier has worked with local composer and sound artist Nicolas Collins to realize 10- to 15-minute versions of three of his most important pieces: I Am Sitting in a Room, Bird and Person Dyning, and Vespers, which celebrates the natural art of echolocation--the way animals like bats and dolphins perceive their environment--and is "for any number of players who would like to pay their respects to all living creatures who inhabit dark places." Saturday, November 18, 8 PM, Galvin Auditorium, Sullivan Center, Loyola University, 6525 N. Sheridan; 773-784-0449.