Like A-ha after an extensive rewilding process: Sigur Ros, at Usher Hall, reviewed

Plus: it’s quite clear that MUNA are going to be huge

What is it with Icelanders and mushrooms? Just weeks after Bjork releases a fungal-themed album, Fossora, Sigur Ros appear on stage with dozens of sporey lights illuminating the gloom.

It’s boom time for mycophiles, but with Sigur Ros the link makes a certain kind of sense. Their aesthetic is not so much post-rock as glacial. For almost three decades the Icelandic quartet have been making large-screen, epically elemental music: celestial choral pieces, art-house concert films, ambient soundscapes and the occasional relatively conventional rock and pop song. Whether aware of it or not, you will have heard ‘Hoppipolla’ on numerous BBC nature documentaries. We won’t hear it tonight, though. Instead, this long show encompasses all that is most entrancing and frustrating about the band. Having previously flirted with arenas, they’re back in theatres, with the forbidding demeanours of men determined to make us work for our pleasure.

The first set is, it’s fair to say, light on toe tappers. This is the music of drift, bloom and sway. The sound of great hunks of ice breaking off from their moorings, birds borne woozily on rising thermals. You either get carried along in the slipstream or remain unmoved. The pieces – ‘songs’ seems insufficiently grand – are built on clean, simple melodic motifs at which the musicians hammer away. Plink-plonk beginnings rise to chest-heaving swells. Singer and guitarist Jonsi Birgisson’s crystalline falsetto mixes Icelandic, English and his own ‘gobbledygook’ vocalese, Vonlenska, to create a sound like wind hitting wire. Occasionally the flow is blocked by mighty squalls and howls, the aural equivalent of heavy weather.

At its best, it’s a transportive rush. At its least effective, it’s all a little repetitive and predictable. The band stand behind their instruments, shuffling to and from work stations between songs.