This is a fastidious selection of American music, blending the known and unknown, from an outstanding choir. Copland’s <i>Four Motets</i> to texts from the Psalms were student pieces written in 1921 for his teacher Nadia Boulanger, who much admired them, but they weren’t published until 1979. Although the mature Copland is vestigial, sung like this they’re impressive. Another rarity is <i>A Stopwatch and an Ordnance Map</i>, a poem by Stephen Spender set for male voices and timpani by Barber in 1940; its subject of a soldier killed in the Spanish Civil War made it topical.</p>

<p>The most substantial work is Feldman’s <i>Rothko Chapel</i> for solo viola, discreet percussion and voices. Written in 1971, it’s almost a funeral march for Rothko, who took his own life the year before. It’s easy to imagine those huge near-blank canvasses round the walls of the chapel at Houston. Interestingly this is not the first recording of <i>Rothko Chapel</i> by the SWR Vocal Ensemble, since it was on their all-Feldman disc in 2001. The new version takes three minutes longer but it’s one of Feldman’s most accessible pieces – eloquent viola-writing and voices alternating mesmerically with percussion. Nobody else could have written it. That’s also true of Bernstein’s <i>Missa brevis</i> and the Reich and Cage works which complete an outstanding anthology, superbly performed: booklet-notes short on information.