How clever to pair sonatas by Giovanni Battista Viotti (1755-1824) and Hélène de Montgeroult (1764-1836). Renowned virtuosos and pedagogues as well as colleagues at the Conservatoire in Paris, they were also duo partners – although neither of their sonatas here is in an equal partnership. Viotti’s score provides only a figured bass line for the keyboardist to accompany the violin; Montgeroult’s was published as a piano sonata with an optional violin part.

One hears precious little Viotti these days (not even the once popular 22nd Violin Concerto), and Montgeroult’s music, long forgotten, is only now being rediscovered. Viotti’s E major Sonata is a cantabile charmer, and Sophie Rosa and Ian Buckle find more sweetness and light in it than Felix Ayo and Corrado de Bernart on what I believe is the only previous recording (Dynamic). They also delve deeper into the dark, lyrical recesses of the slow movement.

I find Montgeroult’s A minor Sonata considerably more involving. Her piano-writing is often imaginatively elaborate and the virtuosity is almost always put to expressive ends. Listen, say, at 1'36" near the end of the first movement’s exposition, where the right hand’s melody flutters in étude-like figuration over a syncopated bass line in the left. The two outer movements are quite agitated in character, which makes the pacific nature of the broad, central Adagio a most welcome emotional oasis. Rosa and Buckle approach the score with improvisatory freedom, pushing to double tempo in the minims at the beginning of the first movement’s development (at 4'36"), for example.

They’re quite free in Mendelssohn’s F minor Sonata, too – perhaps too much so in the main Allegro moderato section of the first movement, as at times it feels episodic – though they also know when to let the music flow with a sense of inexorability, as in the Poco adagio’s sequences starting at 3'27". In the Weber, I find Faust and Melnikov marginally more characterful (Harmonia Mundi, 3/13), though Rosa and Buckle are more successful in juxtaposing the music’s rhythmically effervescent and songful elements.

Rosa’s tone is unfailingly lovely, and she and Buckle have a lovely rapport. Indeed, from the thoughtful repertoire choices to the natural-sounding recording, this Rubicon album is everything a recital recording should be.