The Tibetan word rölmo means “music” in general, but also refers specifically to hemispherical brass cymbals. These may also be known by the name buk chöl or bup chal. These cymbals feature large central knobs with thin leather handles strung through a hole in the center.
The rölmo provide rhythm and structure to the group chants. They are played horizontally by striking their faces together in a tri-part method that includes an initial stroke, an accelerating pulse and a concluding resonating hum.