It’s incredible to think that Mozart’s three ‘Prussian’ Quartets – his final statements in the genre, written for amateur cellist King Friedrich Wilhelm II of Prussia and thus featuring unusually prominent cello-writing – were the results of ‘exhausting labour’, as he wrote to a friend. Their limpid textures and easy melodic lyricism leave precisely the opposite impression. On paper this is music tailor-made for the Chiaroscuro Quartet’s period instruments and clean-lined technical finesse, and the recorded results here bear this out.

The cloaked, dark expressivity of their gut strings works especially well, as do their sparing vibrato and lack of portamento. Add the degree to which they balance, blend and breathe with each other, the results include much deeply ravishing tone quality. The homophonic writing is especially striking – for instance the timbral glow lent to the ascending parallel fourths concluding K575’s first movement, or sections of K589’s Menuetto.

The handling of repeats is also hugely enjoyable – never quite the same yet with changes to the voicing that are often so subtle it’s difficult to put your finger on what precisely has altered. Take the way Ibragimova leans just slightly more into her first figure in the repeat of the second half of K589’s Trio, dialling up the plaintive wistfulness the tiniest notch. In fact, I’d say that the group’s strongest suit is the sheer delicacy and finesse they bring to all three quartets. In that same Trio of No 22 (the Menuetto outer sections are delivered with a delicious sense of spaciousness and metrical wax and wane), the first violin’s impassioned string-crossings are feather-light with a filigree perfection.

Some might find all this delicate voicing a bit too careful when the music really lets its hair down, such as in the Hungarian-influenced finale of K590 – compare the Chiaroscuro to the rough and tumble of the Engegård Quartet (LAWO), or the rambunctious humour and fiery urgency of the Doric (Chandos, 9/21 – although the Chiaroscuro bring plenty of punch in such places as the finale of K589). The Doric or perhaps the Emerson (Sony Classical, 11/11) are alternatives if you’re looking for a slightly bigger-boned romance to the slow movements. Again I’m fully persuaded by the Chiaroscuro, with my personal favourite moments including K589’s Larghetto, where cellist Claire Thirion’s softer-weighted, graceful curve always feels fully rooted in the balance, despite its starring role. All told, these beautifully proportioned readings are well worthy of your time.