Alberto Posadas’ Sombras is a cycle for voice, clarinet and string quartet with darkness at its heart. The opening movement’s pizzicato and sul ponticello scamperings, for instance, are soon replaced by the heavier, insistent grinding of bows on strings, despite attempts to escape its dark gravitational pull. And in “Tránsito I”, soprano and viola smother each other with rival displays, both of beauty and primitivism. The final movement, featuring the clarinet, returns to the opening’s themes of darkness and light. This is a challenging album, but one that yields many rewards.