VALTARI

After a four-year hiatus the ethereal post-rockers of Sigur Rós are back, with a belated studio album that doesn't reaffirm their unique style so much as embalm it under a thick glaze of ambient formaldehyde. "Floaty and minimal", was how front-man Jónsí Birgisson described the music in a pre-release press statement; fans may be left wondering where he stashed the guitars and drums.

In retrospect their previous, more accessible 2008 album "Með Suð Í Eyrum Við Spilum Endalaust" was a not unpleasant detour, showing a warmer side to the normally arctic dirge rock formula all but patented by the band on earlier efforts. The new album charts a more familiar course, but it's less a return to form than a total retreat to some sort of electronic pre-natal womb, reducing the classic sound of Sigur Rós to its barest and most basic essentials.

Expect a surplus of atmospheric textures, some lush amniotic string arrangements, and of course that otherworldly falsetto voice crooning in a language almost but not quite Icelandic. The entire album is lovely beyond words, but not a single minute of it will surprise anyone schooled in post-Eno soundscape design. Jónsí himself already staked out very similar territory in his own 2009 album "Riceboy Sleeps", and this effort likewise resembles a glorified solo project.

A hint of the band's dark energy can still be heard in the slow, pounding crescendo of "Varúð", and to a lesser degree in "Rembihnútur": the only songs with anything approaching an actual rhythm. But even here the circumspect drumming sounds like it was synthetically generated, and elsewhere on the album the energy is dialed back to austerity levels, hardly unplugged but with a couple of fuses deliberately missing.

Maybe that's the point. The entire project might have been an unintended but intuitive portrait of Iceland after its '08 economic collapse, marking the first, hesitant awareness of a band emerging from long hibernation into a new and unfamiliar world. You would sound a little over-cautious yourself, in their shoes.