Hvarf and Heim would fit—snugly, but still—on one disc, but it makes perfect sense that Sigur Rós would split them, because the two EPs represent the farthest reaches of the band's relatively narrow musical spectrum. (That isn't an insult—the spectrum itself is generally incredible.) Hvarf features old music re-imagined: Its title means "disappeared," and it offers new looks at songs largely lost to the Icelandic band's history. The three tracks that haven't been released before in any form ("Salka," "Hljómalind," and "Í Gær") lean toward the metallic end of Sigur's bombastic soundscapes, and the two remakes from the band's overlooked debut album, Von (the title track and "Hafsól") absolutely crush the originals in scope, especially the latter, which stretches to nearly 10 glorious minutes. But the second disc, Heim, is even better. Recorded during an Icelandic tour that included stops with little or no electricity, it gathers three largely acoustic tracks that gain power from their lack of it. One listen to the powered-down "Ágætis Byrjun" should dispel any notion that Sigur Rós gets most of its majesty from volume: The band's music is as beautiful just gliding as it is red-lining.