No song better conveys the vast emotional landscapes that can be found in Sigur Rós’ ethereal post-rock than this, the final song from 2002’s () album. Released on the heels of the acclaimed Ágætis byrjun — which was released in 1999 but didn’t make it to the States until 2001 — expectations were sky-high for ().

Compared to its predecessor’s swelling, celestial sonics, however, () is a considerably starker and more stripped down affair that verges on bleak at times. It all comes to a head on “Popplagið,” which begins in a restrained manner with graceful guitar melodies and gentle strings courtesy of the Amiina quartet. But halfway through, the song suddenly takes a detour into darker territory.

Orri Páll Dýrason’s drumming and Georg Hólm’s bass grow more urgent as Jónsi’s bowed guitar begins to swell and his falsetto becomes a mournful Hopelandic cry. And then, in the song’s final minutes, the band unleashes a musical torrent that’s triumphant, cathartic, and terrifying all at once — a display of Sigur Rós at the very height of their powers.