"Accidents of manufacture," Stuart Dempster calls them—objects that were never intended to make music, but out of which he can coax some startling noises. Like the Crystal Geyser water bottle cap, which when twisted becomes a loudly clacking rattle. Or the large rubber squeeze toy in the shape of a hamburger, which Dempster prods and mangles into emitting long raucous squeals and twitters. Or a yard-long plastic sewer pipe, his concert-hall substitute for the Australian didgeridoo (which he prefers to use only in authentic Aboriginal music), producing the same otherworldly buzzing drone.
Dempster Diving Town Hall, 1119 Eighth Ave., 800-838-3006, www.brownpapertickets.com. $10–$12. 2 p.m. Sun., Oct. 29.
Or the abandoned 2-million-gallon underground cistern at Fort Worden, near Port Townsend, with a magical 45-second reverb time that stretches any note into a seemingly endless plane of sound. It was the site for the trombonist's best-known recording, 1989's Deep Listening (New Albion), a high point of a career spent exploring just what the term "music" can embrace.
Dempster turned 70 on July 7, and birthday celebrations covering nearly a year will climax Sunday at Town Hall with Dempster Diving, a two-and-a-half-hour music-party gathering of friends, colleagues, and mentorees, who will play all over the building, including in the two main performance spaces. Participants will include Trimpin, the Degenerate Art Ensemble, clarinetist William O. Smith, dancer Sheri Cohen, fellow toy-o-phile Susie Kozawa, and others who've been inspired by Dempster's virtuosity, wit, and adventurousness.
Dempster will play a bit, but mostly just sit back and "honorificate," he says, enjoying music written by, for, and about him. Most of his work has a theatrical, even comic side, like the piece he wrote for unicycling trombonist Nathaniel Oxford called Caprice. The trombone's "directional" quality—its ability to point and focus sound like a flashlight beam—makes it a natural for spatial effects, so Oxford will circle the aisles within and behind the audience, cycling on and off Town Hall's stage via specially built ramps.
At his quiet house on a tree-lined Wedgwood side street, Dempster showed me his collection of curious sound makers. First, a pair of dung chen, Tibetan horns made of brass and nickel that telescope to about 7 feet in length. From there to the chirps of a toy cell phone and the squawks of a plastic bike horn—Dempster's removed the bulb and blows into it directly. Under the living-room grand piano sits a battered brass contraption; it couldn't be—yep, it's an ophicleide, an instrument in vogue around 1840 until it was replaced in the orchestra by the more reliable tuba. A friend lent it to see what Dempster, ever game, could get out of it. After a few coarse blats, and some clicks from its ridiculously cumbersome key mechanism, we understand instantly why it became obsolete.
A fairly conventional musical upbringing— piano lessons, school band—was jolted by a band director at the Bay Area's El Cerrito High, a "nutcase," Dempster recalls brightly, who turned his students on to Spike Jones and organized "an after-school jazz band that was about 20 years ahead of its time." This led to a stint in the Oakland Symphony, participation in the Columbia recording of Terry Riley's minimalist landmark In C, and, in 1968, the trombone professorship at the University of Washington, where he literally wrote the book on the instrument's avant-garde capabilities (The Modern Trombone: A Definition of its Idioms, 1979).
As an improviser and composer—"sound gatherer" is the term he prefers—Dempster has retained the enthusiasm and curiosity many musicians seem to have lost by graduate school. He relishes introducing listeners to new sounds—"That'll clean a few ears," he says of his Caprice—but his work is never about aggression, the enlightened bestowing superior wisdom on the proles. He beckons rather than confronts. Let's see where this leads, he seems to say. The Town Hall lineup is testament to what an engaging guide he's always been on these trips to the unknown.