The Japanese sound artist ASUNA, who emerged from Tokyo’s experimental music scene, begins his site-specific listening experience with a single note. While attendees walk around the space, which is crowded with 100 toy keyboards arranged in a circle, ASUNA plays another note on another keyboard. And then another. And then another. The frequencies multiply and reverberate within the gallery space as ASUNA reaches 100 notes, creating a “sonic bath” at the Brooklyn Academy of Music. —J.D.