Beethoven started it, the piano’s duologue with the cello, in 1801, with his Seven Variations on “Bei Männern, welche Liebe fühlen” from Mozart’s Die Zauberflöte. Beethoven himself, and many composers from Brahms (1862) through Lera Auerbach (2002) continued to ornament this form. In 1968, Jacqueline du Pré and Daniel Barenboim, with their recording of Brahms’ Cello Sonata no. 1, reigned as the power-couple of the genre. Alisa Weilerstein and pianist Inon Barnatan, to judge by the power of their performance this afternoon in Koerner Hall, deserve to inherit the mantle.

Without meaning to suggest anything about their actual relationship, on stage, Weilerstein and Barnatan have tremendous chemistry. She is elegant and flamboyant as Rita Hayworth. He is charming and smooth as Fred Astaire. Their opening exchange in the dance-like Allegretto of Beethoven’s variations was a gentle, lyrical suggestion from the piano that Ms Weilerstein voiced back in a similar tone with a toss of her hair and a playful diminuendo. The playfulness continues in imitative accents through the counterpoint in the first variation, taking a turn into the sublime during the lyrical third variation where Weilerstein’s cello plays the deep masculine part and Barnatan’s piano sings the feminine-sounding lines. The last variation includes unexpected shifts from lilting duet to fiery confrontation to a Mozartian chase that the cello shifts into low gear before the duo finale in a single, unison burst.

Benjamin Britten’s Cello Sonata in C major was composed around 1961, after he’d heard Rostropovitch in London performing a cello work by Shostakovich. I mention this because I did not connect with our duo’s stuttering treatment of Britten’s prickly opening Dialoguo. Weilerstein vehemently led into turbulence, Barnatan lightly shadowed her, at times lyrical, then rising in alarm to a vehemence of his own. This was playing virtuosic, but not touching, until into the Scherzo: pizzicato, where the cello began skipping over the sonic surface, the piano rippling underneath and the madcap spirit of Shostakovich seems to be coming through. From there the players shared the rising intensity of the mournful Elegia as it faded into the lento section that follows: pitches of piano fall on the ear faintly as raindrops, and the cello is like those drops sliding down a misted pane, and Weilerstein looks like she is going to cry. The concluding Marcia and Moto perpetuo are Britten alive and wild with the the mocking spirit of Shostakovich, the crazy clowning disposition of Prokofiev. Together they careened off into an eerie toyland fantasy that built, through the blurr of octaves in Barnatan’s hands and Weilerstein’s discordant bowing, into a final bang.

Next they gave us a suite of seven selections from Shostakovich’s 24 Preludes transcribed for cello and piano by Lera Auerbach. The work is filled with a deeply Russian dissidence – the piano icy and dark, the cello penetrating deeply as if into the peace of death. The subsequent rainbow of moods exhibits a gritty, sarcastic dance, more clowning, melancholic cello blues, a Russian lullaby, a horsey gallop, a pastoral passage reminiscent of the great theme from Elgar’s Concerto, nostalgic melodies, and a roistering, high-stepping folk-tale. Good stuff.

After so much music, one felt more, especially 30 minutes of Rachmaninov’s technically daunting Cello Sonata in G minor (1901), might be too much of a good thing. However, the beautifully melodic two-note figure rising from Weilerstein’s cello created a singing line that dispelled all doubts. There was, admittedly, a melancholy flavour to this line, but that was swept away as the lyric music flowed into a pastoral mode between strings hammered on the piano and strings bowed on the cello. Ms Weilerstein is something to watch: at times she is abandoned, hair flying in her face; and sometimes her attention is like a cat watching a mouse. The Scherzando was piano twinkling through charcoal strokes of cello and the dramatic alternation of moods from drama to dance. The theme of dance continues in the Andante with the duo moving like lovers drifting through an empty moonlit ballroom. The Finale tugged at the heart as Rachmaninov's music took on the broad sweep of music that, like Mahler’s “American” compositions, tell of the pleasure and the pain of an old mind discovering a new world. Whatever the duo Weilerstein and Barnatan have to tell, I look forward to hearing.