To mark Independence Day here is a disc that makes the mid-20th century in the US seem a pinnacle of choral music.

Bernstein’s Missa brevis, in a scorching performance, hits heights of rhythmic ecstasy. Barber’s Agnus Dei, the choral version of his favourite Adagio for strings, tears at the heart with its mournful sentimentality.

Randall Thompson’s gently radiant Alleluia and Fare Well deserve to be popular choral favourites.

Even Copland’s student settings have a certain comforting appeal.

The brilliant Polyphony and its conductor, Stephen Layton, can do no wrong.