Even without stalwart bandmate Stephen Stills, David Crosby and Graham Nash have a magical sonic chemistry. On their second duo album, they cover new ground while maintaining their peerless vocal blend. Hearing Nash's airy tenor entwine itself around Crosby's warm, woody tones is a thrill unto itself, but when they take a turn into fugue-like territory on the a cappella opening of "To the Last Whale" or explore the tricky dance between mortality and transcendence on the luminous "Carry Me," the experience is even richer.