Anima Eterna perform Schubert’s ever-lovable Octet on instruments largely from the early 19th century. And these instruments are wild. Lisa Shklyaver’s clarinet wails at the introduction to the finale but sings in the gorgeous cantabile of the Adagio. Ulrich Hübner’s natural horn can blast his colleagues into submission. There’s a graininess to the strings and a glorious hollowness to Beltane Ruiz Molina’s double bass. Modern instruments have developed to be better-behaved and to promote blend but these players exult in the timbral differences between them.

A few decades ago this sort of exercise would be have been marked by squeaks, thin tone and tuning that verged, let’s say, on the ripe side. The advances in playing techniques since then, though, are evident in a performance such as this, where the challenges of gut strings and pre-Böhm woodwinds have been met and surmounted. That string graininess can be spun into sugary sweetness, not least by leader Jakob Lehmann’s application of portamento as an expressive device. Molina’s bass is the firm foundation, with clarinet and horn taking the lion’s share of melodic duty over the fertile topsoil of upper and middle strings. If you’re on board with the historical instrument project then the tonal heterogeneity of this ensemble, complete with occasional key noise and bass pizzicatos that slap and buzz against the fingerboard, will have bags of appeal. The music, of course, is glorious; the evident joy with which it is performed is delicious.

Berwald’s Grand Septet is slighter than the Schubert – with which it’s roughly contemporary – but is presumably modelled on the identically scored Septet by Beethoven, which also provided the seed of Schubert’s Octet. (Second violinist László Paulik sits out for the Berwald.) If it doesn’t have the almost overwhelming melodic fecundity of the bigger work, it’s full of the Swede’s individual approach to harmony and details of scoring.

Isabelle Faust and a group of high-profile colleagues recently recorded the Schubert on period instruments, presenting a more demure, inward Octet. But the steampunk brazenness of this Belgian ensemble – more closely recorded, too – is its own advertisement.