Gamelan is traditional ensemble music from Indonesia that relies heavily on mallet-struck metallophones and drums called kendhang, with other sounds emitting from bamboo flutes, xylophones, and the bowed instrument rebab. It can sound chaotic yet regimented or serenely mellifluous, but it is never less than mesmerizing. Gamelan Pacifica have long been Seattle’s foremost practitioners of the style, and for this concert, they’re collaborating with Central Java musician Darsono (making his Seattle debut), as they perform pieces from his region’s repertoire. In addition, Stranger Genius Jessika Kenney will lend her vocals to the proceedings. by Dave Segal