Momentum was effortlessly sustained through the deliberated breeziness of the second movement.
Then, with the sonorous calm of a Minuet and Trio still fresh in our ears, Beethoven's Finale asserted itself with amiability and the occasional storm.
In an evening celebrating the music of the trio's home town, Fur Balint Andras Varga, by the 41-year-old Johannes Maria Staud, revealed what we might expect from a Third Viennese School of composers.
Last year, conductor Franz Welser-Most likened one of Staud's orchestral works to looking through a magnifying glass; Friday night's performance was just that, within a more modest canvas.
This music is generous in its range of expression. Curling dialogues, synchronised with Balanchine precision, eventually led to a Slavic-tinged lament from violinist David McCarroll.
Instrumental lines often had a Viennese lilt to them, brutally cast aside for Mendl's visceral splatter-and-pound attack on his instrument, perpetrated with an avant-garde flamboyance refreshing in these austere times.
After interval, Schubert's E flat major Trio was a return to calm. Here was utter perfection, with a first movement that balanced cascades of rippling piano with a second theme of immaculately clipped prettiness.
Every mood was captured, nowhere more so than in the Andante where, despite the blue skies promised in major-key interludes, a poignant minor theme, slightly klezmerish, set a more sorrowful tone.
After two minutes' applause, Mendl explained that it was the group's policy not to play encores after this work. Many, I am sure, will be eagerly awaiting Radio New Zealand Concert's broadcast, perhaps with a CD at the ready to provide their own envoi.
Classical music
What: Vienna Piano Trio
Where: Auckland Town Hall
When: Friday.
