Takk... , the title of Sigur Rós' new album, means "thanks" in Icelandic. Perhaps it signifies gratitude to fans for not falling asleep over the course of their last two LPs. See, the band's impressive discography has been high on melancholy and talent but short on range. On Takk, things are noticeably different; the hopeful notes of the title track set the tone for an hour of pop tunes as an Icelandic symphony might perform them. Although these songs are not standard verse-chorus affairs, the upbeat "Hoppípolla" and snare-driven "Gong" have rhythms that flirt with hooks--even with sounds this strange and adventurous, those tracks almost sound ready for the radio. And at the conclusion of "Glósóli," cacophonous percussion set against clanking bells might shock longtime fans when it takes the band to a new, deafening sonic level. Strong pulses and shorter running times replace the ominous wails of the old albums' creeping 12-minute tracks. Even the bulk of the album's lyrics are Icelandic, a departure from using the invented language Hopelandic (and bonus points if you can actually differentiate between the two). Thankfully, the signature indecipherable falsettos and strange guitar whines make the move into their new surroundings with ease. This is what a mood swing should sound like.