The Ozark Mountains British Brass Band will perform a free concert at the 80th anniversary celebration for the Eureka Springs city auditorium (known as "THE Aud")Sunday Sept. 13 at 2 p.m. There will also be an open house, a slide show featuring historic photos, and free refreshments. A British-style brass band has a unique sound owing to the specific instrumentation--all parts are written the treble clef except the bass trombone, and the instruments are all conical-bore, where the tubing starts small and gradually increases in diameter; they produce a mellower tone than cylindrical-bore instruments. The Ozark Mountains Brass Band was established in 1995 by Tom Raber and Clay McCartney. Daniel Hodge will conduct the band.