Icelandic orchestral-rock group Sigur Rós should be one of the most reviled acts on the pop landscape. Its songs typically last eight minutes, it titles albums with symbols, singer Jon Thor Birgisson makes up his own language, and, last but certainly not least, it's an Icelandic orchestral-rock group. Yet nobody else making records today sounds like Sigur Rós. And nobody's making records as gorgeous and as mind-blowing. With its fourth album, Takk ... , Sigur Rós fortifies its position as one of the few new-millennium bands that bothers to craft entire sets of songs, an escalating rarity in the iPod age. The album's 11 cuts are connected by a harmonic, if not lyrical, thread. (Birgisson at least strings together genuine words this time around.) The melancholy horns that join the parade on "Se Lest" eventually give way to "Saeglopur," a momentous set piece that erupts in a discharge of choral voices, horns, strings and bowed guitar. And the ten-minute "Milano" amounts to modern classical music played with a rock-band aesthetic. (And, yes, Sigur Rós actually named its new songs; 2002's ( ) included eight untitled tracks.) If all this sounds similar to 2000's breakthrough CD, Ágætis Byrjun, well, it sorta is. But atmospheric mood music has never sounded so elevating or inviting.