More happens in the first 30 seconds of Kveikur (XL), the seventh LP by slow-melt Icelandic trio Sigur Ros, than in some 30-minute stretches of the band's other albums. (This is hyperbole, but not by much — while not quite John Cage in their embrace of negative space, these are the same guys that made 18 seconds of silence into a Rauschenberg-like white-canvas calling card.) Five crashing notes serve as notice that the E.T. finger-touching of 2012's Valtari has given way to a more hostile kind of sensory takeover. It's a stimulating departure, if not as captivating a trick as what Jonsi Birgisson and company started out doing, transfixing listeners in a gobbledygook language with a pair of parentheses and the nothing in between, making outermost Scandinavia sound like the farthest reaches of outer space. As with fellow true post-rockers Explosions in the Sky, Sigur Ros' bowed strings and stratospheric soundstages are malleable enough to convey any emotion one wishes to attach to them, making the band a first-call soundtrack option for everything from modern dance to nature documentaries to The Simpsons. Kveikur and the new Radiohead-esque "Oveour" have more limited applications — a recent cameo on HBO's Game of Thrones hits the bull's-eye — but it compensates with blunt force. Tickets $49.50-$128.