Bartók’s Sixth String Quartet, begun shortly before Hitler’s forces invaded Poland in 1939, conveys a heartfelt elegy for its composer’s mother and an overriding sense of sadness at mankind’s inhumanity.

Paul Lewis and the Vertavo String Quartet turn towards the better angels of human nature in Mozart’s Piano Concerto in A K414, a work of irresistible optimism, and Dvorák’s folksong-infused Piano Quintet.