As Decca is somewhat shy about letting on exactly who the sisters Sarah and Deborah Nemtanu are (at least in the context of the otherwise useful CD booklet-note), I can tell you that they’re young, Paris-based, have been playing together since childhood and recorded the present complete set of Bartók’s 44 Duos for violins last year. You can see them perform ‘Bagpipes’ (No 36) online, a quite different reading to the one included here, which gradually accelerates into action. I prefer the online version.

Bartók’s Duos (1931) were not, strictly speaking, intended for concert performance, but rather serve the same purpose as his piano cycles Mikrokosmos and For Children, in other words as teaching material that tackles various levels of performing difficulty head-on. The music’s appeal lies in its folk origins – Hungarian, Romanian, Slovakian, Serbian, Ruthenian, Arabic and Ukrainian. The Nemtanu sisters blend well, their tones ideally matched, their style happily admitting ‘gypsy’ elements such as portamento and vigorous rhythmic attack, eg in No 35, ‘Ruthenian Kolomeika’, where they also bring a level of humour to bear. They inflect the music imaginatively and grant it full concert status, meaning that its ‘functional’ aspect fades in the light of its high performance value.

But how do the Nemtanus rank alongside their various CD rivals? Compare them with Barnabás Kelemen and Katalin Kokas in the ‘Arabian Song’ (No 42), and the latter pair display a firmer grip of the music’s sawing rhythm, the Nemtanus opting for a freer approach that doesn’t quite avoid a sense of randomness.

So, excellent as these newcomers are, I’d hesitate to elevate them above long-standing favourites. I’ve always enjoyed the sugar-and-sour-cream approach of André Gertler and Josef Suk. Likewise wildcard Sándor Végh with Alberto Lysy, while Itzhak Perlman and Pinchas Zukerman score highest for beauty of tone and security of attack. But the Nemtanu sisters leave a strong impression: you can happily listen to them at a single stretch and their playing is captured in very well-balanced sound.