Kings Place’s Out Hear series of contemporary music is second to none in London, but these concerts – though never less than interesting – can also be strangely low-key. In a lot of ways, this Wednesday’s Out Hear concert, the last this season, was quite a big deal: a rare visit to London from leading contemporary ensemble Klangforum Wien, containing a world première. And yet everything seemed slightly muted, a little boxed-in inside the always dark Hall Two, not aided by the prominent background humming of some unidentified machine. Perhaps that sound was the audience’s collective brains, as there was certainly a lot to think about.

The piano quintet from the Klangforum played as outstandingly as should be expected from such a prominent group, packing a lot into this slight programme of three contemporary compositions. The première was by Roberto David Rusconi, prefaced by some poetry on similar subject matter by Isobel Dixon, and before this were pieces by Bernhard Gander and Klangforum founder Beat Furrer. It was the second in a two-concert series organised by Rusconi entitled Music in the Space Time Continuum.

It’s clear enough that all music, as well as everything else that exists, is in the space–time continuum. We were being asked, I think, to consider music specifically in the context of 20th- and 21st-century advances in physics; to consider the production of sound in a world where time and space are essentially as one. This, at any rate, was the point of departure for the programme notes, which also claimed that the project “underline[d] the need to think through the whole musical establishment”. In other words, the concerts’ theme was both vague and probably too ambitious for something so brief (especially when one of the pieces was ostensibly about a comic-book superhero). The notes concluded by stressing the need to “reconnect to the communication of pure poetical universes” – presumably, an entreaty to consider music in the abstract, devoid of external agendas. But this was rather comprehensively undermined by the two paragraphs of dense theoretical text which preceded it.

I found Rusconi’s piece itself equally difficult to disentangle from its conceptual underpinning. Entitled De materia nigra et obscura, it concerns itself with the discovery of the Higgs boson, the elusive “God particle” which was confirmed to exist in March this year. It begins, and is permeated by, a spacious clatter of sound based around some low, loud piano notes, and the sound created is opaque, mysterious, superficially similar to its subject matter. Beyond this, the piece gave me little to grab onto; I sensed only that if there was a deeper connection to physics, it was a connection as complex as the physics itself. I felt too overloaded by concepts to be able to enjoy the experience. Isobel Dixon’s reading from her sequence Dark Matters was an interesting interlude, but it did not engage productively with the musical content.

Beat Furrer’s piano quintet Spur (1998) was just as demanding on the ear as Rusconi’s, but felt a lot more open to interpretation. Drawing some extraordinarily soft piano playing from the impressive Joonas Ahonen, this catalogue of restive murmurs and silences made a fascinating fifteen minutes. The title translates to “Traces”, and there were hints of other sounds here, other ideas; the occasional Brahmsian broken chords in the piano part; the faintly Webernesque precision of the string parts. But whatever the title hinted at, the music also told its own, strange story.

The story of Khul was rather different: Bernhard Gander’s 2010 piece for string quartet is an “adaptation” of comic book character The Hulk, translating his violent, extreme changes of mood into abrupt musical contrasts. Bright, cartoonish rhythms mixed with harsh sonorities. It was a quirky, fun piece, though I can’t claim it made me think much about the space–time continuum.

The Klangforum players excelled throughout, especially relishing Spur, with which they have had a long association, and to which they brought a subtle, unexpected lyrical sensibility. The programme was certainly an effective showcase for these five talented musicians – fingers are crossed that the Klangforum will be back in London at another space-time soon.