I have an abiding memory of attending a Norwegian Soloists’ Choir concert that journeyed through a tricky smorgasbord of Messiaen, Brahms and Xenakis, during which the singers tuned the start of each piece silently, using just their brains and the final chord of whatever piece went before. That programme, like this one, included Xenakis’s Nuit. For more proof of just how technically astonishing this ensemble can be, go to 3'58" in that piece and hear voices emerge from a pitchless cackle into an upward glissando that alights elegantly upon a perfectly tuned minor second. Is there anything this choir can’t do?

It would appear not. But while the more difficult pieces here (six out of the seven tracks) bring the most imposing singing from the choir, the song-like purity of Per Nørgård’s Drømmesange shows just how attractive and unaffected the ensemble’s ‘plain’ delivery can be too (for more of that, hear its staggering folk-song disc ‘White Night’ – 9/11).

So what have we, besides those works already mentioned? The galaxy of sounds that is Lachenmann’s Consolation II (listen to what the singers are up to on the work’s fringes), two pieces of good-vintage Saariaho (the quasi-medieval Überzeugung from 2001 and Nuits, adieux from 1991, the latter feeling somehow aligned to the earth’s core) and Nørgård’s Singe die Gärten, mein Herz, die du nicht kennst (a sample of the Third Symphony). And my personal highlight, Alfred Janson’s Nocturne, a piece that asks big questions with Sibelian compactness of structure and that manages to make a root-position minor chord sound utterly terrifying.

There is delicacy, sensitivity, richness and detail in each performance here (no prizes for guessing the disc’s theme) and excellent sound that gets to the many corners of each score. Add to that extraordinary imagination in the singing, individually and collectively. Such imagination is what defines this wonderful ensemble; the programming here tells you that before you’ve heard a note.