Ešenvalds combines a Latvian folk song, sung by a solo tenor [soprano], with less fearful, and factual, observations of the Northern Lights by two nineteenth-century Arctic explorers, Charles Francis Hall and Fridtjof Nansen. In a lilting triple-time metre throughout, with tuned glasses played by the singers adding an unearthly aura at salient points, the music is full of wonder, with an especially dramatic moment of revelation early on. Twice, a moment of special transcendence is summoned up by...