The two violins, in tender but austere duet, launched the Adagio, while the Finale emerged from the darker, brooding tones of Cassidy and cellist Jacqueline Thomas.
This closing movement brought up memories of music already heard, reminding us that Shostakovich, in this 1946 work, had been deeply affected by the flagrant inhumanities of the Second World War.
After interval, Beethoven's A minor Quartet of Opus 132 was a revelation.
We were in thrall from those first exquisitely balanced chords. Throughout, similar textures, especially in the almost mystical stillness of the central slow movement, were subtly voiced and nuanced.
The rank contrasts in Beethoven's late quartets might well outrage the unwary. Even American scholar Joseph Kerman marvelled at those "profoundly forced" interludes in this Adagio molto. Tonight the primary colours and bold flourishes of these pages glowed with authority.
There was so much glorious detail in this performance. The quartet did full justice to Beethoven's instruction, "with the deepest feeling," in the Adagio molto as well as evoking an eerie folkishness in the second movement and thrilling us in the Finale's brutal rushes.
Elgar's Chanson de Nuit was a generous and beautifully understated encore. Best of all, Rowland's introduction, talking of this as their last concert in New Zealand but maybe not forever, left us impatient for another visit.