In conversation with Petroc Trelawny at the fourth of the Proms Chamber Music concerts, the 25-year-old Norwegian trumpeter Tine Ting Helseth casually dismissed her ten-piece brass ensemble tenThing’s all-female set-up as “just a gimmick”. True though that may be in her eyes – she and some brass-playing friends at music college were sat in a string orchestra concert and thought it’d be fun to perform similar repertoire, and “hey, wouldn’t it be funny” if the players were all female – the potential that she and her nine colleagues have to make brass playing relevant, even fashionable, and appealing to a younger audience (especially girls; she is well aware that ladies are under-represented in the brass sections of many an orchestra), is vast indeed.

In appealing to new audiences, tenThing completely reinvents the idea of a brass band. Immediately obvious was their style – no uniform, no “concert dress”; the ladies wore casually glamorous outfits and heeled shoes, perfecting the “work-to-evening chic” look so often pressed upon us by the fashion pack. It’s also not your standard set-up: four trumpets (plus or minus a flugelhorn), a French horn, three trombones, and a tuba player There was also no set form to the group: with the exception of the tuba player, the players stood as they played, and even introduced choreography into the mix. It might be shallow to mention that they are all beautiful, too, but they are, and it is undoubtedly an asset – though unlike some famous faces, it is their musical talents that sell records. Music-wise, the concert was all about arrangements, rather than any familiar brass-band repertoire; a Norwegian guitarist named Jarle Storløken is the group’s go-to arranger. As Helseth put it, the group approaches him, says “‘how about this?’ And he says ‘yeah’.”

It is hard to believe that Storløken has never touched a brass instrument. The recital began with arrangements of pieces by Norway’s most famous son, Edvard Grieg, which tenThing played by heart, including a bracing version of the prelude to the Holberg Suite, and a humorous Grandmother’s Minuet, in which the tuba player played grandmother as the others surrounded her, in turn sneaking up to her and then moving away. We were then introduced to composer Diana Burrell, one of several composers who have written specifically for the group. Her composition Blaze, a BBC commission given its world première here, was designed to exploit the homogeneity of the brass instruments’ sound whilst also providing opportunity for the players’ virtuosity to shine through. It was an exciting piece – less of an all-out blaze of sound than its title would have one believe; it was far more a curated tour round the instruments’ individual and collective capabilities.

The genres of music arranged for tenThing seemed to know no bounds: we had already had folk music from the group’s native Norway and something contemporary; now we were treated to a selection of tunes from Kurt Weill’s Threepenny Opera Suite. The combination of muted and unmuted instruments made it seem as though there was an entire orchestra on the stage: at one point, one of the trumpeters, muted as the others played without mutes, sounded convincingly like a clarinet, and then later on like a saxophone. Have a watch online – you can see all the Monday concerts on the BBC site for the next few weeks – and you’ll hear what I mean: truly unnerving (but also very, very cool).

What was also spectacular about this recital was the way in which tenThing embraced the quirks of Cadogan Hall to full effect, utilising the various surfaces (wooden panels, plasterwork, and polished flooring) to produce subtle – but noticeable – differences in acoustic. The choreography was not simply a stunt, either, for in facing away from the audience and then turning slowly round, the group was able to alter the dynamics of the music and the timbre without much change to the physical production of sound. This worked especially well for Bizet’s Suite no. 2 from Carmen, in which there was consequently no uncertainty about the music’s sudden changes in mood. Helseth’s guilty pleasure, tango music – here represented by Astor Piazzolla’s Oblivion – also benefited from this clever trickery, but here the choreography also took on a Latino flavour.

It’s not quite a chamber ensemble or a brass band, and it’s certainly not an orchestra, yet tenThing seems to be able to morph effortlessly into each of these these like a benevolent Jekyll/Hyde, whilst its approach is musically appealing and entirely refreshing. tenThing’s enthusiasm for its art is infectious, perhaps because the group only comes together a handful of times each year – members have time to pursue other interests between concerts. tenThing does what it likes, not what inherently appeals to the audience or is going to draw in the most revenue, and that makes the ensemble worth watching. This recital in particular was riveting – great music, great players, and great fun to boot.