Sure, Jimi Hendrix smashed guitars, but Sigur Rós frontman Jon Thor Birgisson plays his guitar with a cello bow that, in fits of unflinching fury, he shreds against the strings. With just a few fibers remaining, he goes on to saw out chiming chords. It’s a feat he performed twice at the Icelandic quartet’s sold-out Berklee Performance Center concert last Saturday, the first of two Boston shows that launched their American tour.

Before the scrawny kids even stepped onto the stage, a reverent mood was established by a stroke of theatricality: a stagehand lit candles and arranged them among the instruments. But the soft flames were a deceptive prologue to the flashy spectacle that followed. It’s surprising that these musicians remain anonymous on their albums (their names don’t even appear in the packaging of their latest Fat Cat release, ( ), let alone in song-title credits or liner notes), because they certainly came across as natural showfolk. As looped videos of abstract animated digital images and footage of birds and children played, Georg Holm’s rumbling bass anchored the almost two-hour set. Blending new songs with tracks from Ágaetis Byrjun (PIAS) and ( ), they moved from the requiem-like " Samskeyti " (a working title for the new album’s track #3), which was marked by Kjartan Sveinsson’s hook-laden piano grooves and piccolo arpeggios, to cataclysmic, hard-ripping surges during which at one point Orri Pall Dyrason’s aggressive drumming knocked a cymbal loose. This all played out to the accompaniment of a string quartet whose members, all women, were far from formal in their performance. Despite the distractions, it was not difficult to focus on Birgisson, who switched between guitar and synthesizer when he sang, his shimmering falsetto beginning at a whimper and crescendoing to a climax.

Yes, Sigur Rós’s lyrics are all in " Hopelandic, " an invented language that sounds like prog-rock’s answer to scatting, but that was no barrier to understanding. Birgisson wore a crumpled expression on his childlike face that broadcast urgency, a look that clarified his simple plea for us to be transported by his ethereal siren as it summoned us to a place both foreboding and inviting.