The tranquil beauty of Emma Houton’s vocal harmonies, self-recorded here in eight parts a cappella, would be enough to make her work worth attention. But this debut release does not settle for ambient sameness; instead, she shapes her singing into a varied and rewarding landscape. “Bow and Balance” is the center of gravity, where an Irish murder ballad holds the foreground while the background vocals develop from a simple repeating pattern into a panorama of luminous sound.