When Mozart’s earliest ‘sonatas for keyboard with violin accompaniment’, K6 9, appeared in Paris in 1764, father Leopold wrote of the ‘furore they will create in the world when people read…that they were composed by a seven-year-old child’. Even allowing for a spot of paternal help, the diminutive wunderkind already reveals himself master of the rococo-Italianate lingua franca; and if some of the movements here and in the sonatas K15 and K29 do little more than trickle amiably through the motions, the embryonic opera composer is already glimpsed in the chirpy exchanges between keyboard (which in these works always controls proceedings) and violin.

As in the first volume of their complete sonata series (5/16), Tiberghien and Ibragimova palpably delight in their opportunities for witty repartee, whether in the scintillating finale of K15 or the darting ebullience of K7’s opening Allegro molto. Cultivating light, limpid sonorities (violin vibrato used only for occasional effect), the pair shade and phrase imaginatively without compromising the music’s essential innocence. They touchingly realise the delicate sensuality of K7’s Andante, while their rhythmic buoyancy and shared sense of fun animate more than one movement that seems routine on the page.

The mature sonatas K305 and K376 – true egalitarian dialogues – are of course on a different artistic plane, as is the unfinished two-movement sonata, K402, consisting of a broad slow movement and a tortuous chromatic fugue (like several other Mozart fragments, this was completed by Maximilian Stadler). Balancing what the 18th century dubbed ‘taste’ with vivid moment-by-moment characterisation, Tiberghien and Ibragimova strike me as nigh-on ideal. I’ve never heard the 6/8 opening movement of K305 done with such mingled grace and devil-may-care exuberance – a real whiff of the chase here. The pair’s variety of colour and inflection, with every repetition a cue for new thinking, is delightfully heard, too, in the outer movements of K376. I love the different meanings they bring to the Rondo’s demure opening theme on its successive appearances, finally transforming it into a lusty folk dance. In the Andante, taken flowingly, Tiberghien matches his partner in the purity of his line-drawing to create a chaste operatic love duet by other means.

Rachel Podger and Gary Cooper (Channel Classics) make a strong case for period instruments in their complete Mozart sonata cycle. But if you prefer a rather less abrasive sound world, this ongoing series from the symbiotic partnership of Tiberghien and Ibragimova will be hard to beat. The recorded balance is ideal, while Misha Donat contributes a typically enlightening note.