It was unusual enough that a vast majority of the fans could not understand any of the lyrics. At the start of Wednesday's concert by experimental Icelandic rockers Sigur Rós, the crowd also couldn't even see the band.

The mesmerizing two-hour performance at Roy Wilkins Auditorium began with a white curtain wrapped entirely around the stage, with shimmery video images projected onto it. That curtain didn't drop until the second song, "Ný Batterí," reached its climax. By then, the audience was already under the music's spell.

Nearing its 20th year, Sigur Rós has employed arty film montages and candle-like stage lighting going back to its unforgettable show at the Woman's Club Theater in Minneapolis in 2001, but Wednesday's show took it to another level.

The band employed a giant, curved Jumbotron backdrop and all kinds of swirly lights to enhance its cinematic sound. It evoked comparisons to the dazzling eye-candy display that fellow European crossover band Muse puts on, except in this case it didn't distract from any lack of luster in the music.

Sigur Rós' atmospheric orchestral rock proved so compelling Wednesday, the 4,000-plus fans — just shy of a sellout — didn't lose any interest during the four unreleased new songs the band dropped into the set. That included the lush, mellow opener "Yfirborð," as well as the grinding pre-encore finale, "Brennisteinn." Each hails from the album "Kveikur" not due out until June.

The most impressive aspect of the set, though, was how capably the band maintained its all-important intimate charm even in the cavernous, dank Roy Wilkins Auditorium.

Case in point: The auditorium was pin-drop quiet during some of the mellower, more ambient tunes such as last year's ambient gem "Varúð" and especially "Vaka."

The latter song provided a fine example of singer/guitarist Jónsi Birgisson's siren-like, goosebumps-inducing voice — still the most impressive falsetto in indie-rock (sorry, Bon Iver).

Birgisson's other unique talent — using a cello bow instead of a pick on his guitar, often with eerily beautiful results — was masterfully employed with help from an 11-member auxiliary band that included string and wind instrumentalists. The encore starter "Glósóli" sounded extra urgent and dramatic, and the night's most accessible tune, "Hoppípolla," was even more richly layered in melodies.

A sign of how devout these guys are to their native tongue, they even sang "Happy Birthday" to one of their band mates in Icelandic. That was just one of many ways Sigur Rós stayed true to its roots Wednesday.

Full set list at startribune.com/artcetera

Chris Riemenschneider • 612-673-4658