From my vantage point in the second tier of the Royal Concert Hall, the audience below appears to be disproportionately bespectacled. A Sigur Rós show is not like other gigs. It can be hard to know what to expect, how to behave, or what to wear. One woman in the stalls resembles a mirror ball.

The auditorium, like Nottingham itself, is drenched in fog. It makes their lighting behave like their music: a pure core surrounded by elements that dissipate and distort. Less satisfyingly, it creates miniature lightening strikes from those who don’t know how to switch their phone’s flash off. Other than the phone-flashing, the audience is remarkably well behaved for a room of (the weirdly specific) 2,499 people. It’s the only public place where I don’t hear a single yell of “You reds” all weekend.

When the band first emerge, it’s strange to see the other-worldly falsetto emerging from the body of a human. I had assumed that lead signer Jonsi was an elf with a record deal. The power and clarity of his voice contrasts with the palette of thundering distortion, metallic grinding, enveloping drones, and near-tribal drums. It’s like The Snowman meets Silent Hill.

Some bands may measure their reception by the volume and rowdiness of a crowd. In this instance, the opposite is true. Few acts have the ability to render a huge crowd so silent that the air-conditioning becomes audible. Of course, there was thunderous applause at the end of each song, but in quiet interludes the audience were spellbound. It was less like seeing live music, and more like witnessing atmosphere artists sonically weaving a tapestry of contemplation.

Overall, it was quite different to the last show I saw at the Royal Concert Hall: My Dad Wrote a Porno Live.