It was an absolute pleasure to see The Thing in the smart surroundings of one of my favourite live music venues in Vienna, Porgy & Bess. An ambitious piece of programming, for sure, and one that resulted in a fair few empty seats, but it was worth it just to see the way this remarkable group took control of the larger and more formal space with just as much fire and gusto as they did when I saw them at the Blue Tomato. As if that weren’t enough, they were joined for the second half by the ubiquitous Ken Vandermark, who added his unique swing and pulse to the controlled onslaught wrought by the core trio of Mats Gustafsson, Ingebrigt Håker Flaten and Paal Nilssen-Love.

The Thing present the listener with a delicious conundrum: where does the composed end and the improvised begin? Famously named after a Don Cherry tune, they seem to get a free pass from hipsters by virtue of what a fawning piece in The Quietus recently described as their “affinity with alternative rock”. On the contrary, what makes The Thing so precious and unique is the way they use composed sections as a springboard for wild, unapologetic free jazz.

Case in point: the opening number tonight, an old zydeco tune called “Call The Police” by Stephanie McDee. The original consists largely of an addictive accordion riff repeated ad infinitum. Gustafsson leapt on this riff with glee, transforming it into a juggernaut tenor sax statement while Nilssen-Love fired off intricate polyrhythmic beats and Håker Flaten flayed his double bass alive. Elsewhere in the same song, Gustafsson embarked on an extended circular breathing excursion, something I’d never heard him do before despite having seen him play many times. This utterly transfixing solo was a salutary reminder, as if one were needed, that behind Gustafsson’s high-energy attack there lurks a master of jazz technique.

Vandermark’s arrival after the break was the cue for both the grooviest and saddest of the evening’s moods. Effervescent as ever on tenor, the American’s command of the upper register was complemented perfectly by Gustafsson’s swooping baritone low end. Their ecstatic interplay only subsided when Vandermark turned to the clarinet and traced a slow, desolate duo passage with the momentarily becalmed Håker Flaten. Later, as Gustafsson took up the rarely heard fluteophone, Vandermark too was to deliver an engrossing section of circular breathing. As before, there were infectious riffs and melodies galore during this second half, which coalesced into tempestuous group improvisations. Surging restlessly in and out of songform, The Thing are embarked on a thrilling journey where the only certainty is that nothing can be predicted.