In the music spotlight: Sigur Ros

From 1979 to 1997, Cocteau Twins distinguished their Eurocentric alt-pop with Elisabeth Fraser’s hypnotic vocals. Although they were often sung so indistinctly that literal meaning was indiscernible, the emotional impact was deep. Iceland’s Sigur Rós picked up a similar thread beginning in 1994. Jónsi Birgisson named his evocative non-dialect “Hopelandic,” and the band matched his approach to language with its ethereal music.

The band’s sound on earlier releases including “ágætis byrjun” and the enigmatically named “( )” was perpetually out of focus – hymnal and lovely, creating images of ghostly translucence that shimmered at the edges. On 2013’s “Kveikur,” songs like “Brennisteinn” and “Hrafntinna” maintained the sense of musical surrealism but incorporated distressed sonics and lurching, clattering rhythms reminiscent of industrial pioneers Einstürzende Neubauten.

The band’s North American tour will be Sigur Rós’ first headlining run here without an opening act. The luxury of additional time should suit the band’s glacially unfolding catalog pieces well, with more opportunity to linger over harmonious swells and dwell on spine-tingling peaks.

Sigur Rós is also touring for the first time in its core trio format of guitarist and vocalist Birgisson, bassist Georg Hólm and drummer Orri Páll Dýrason. Although the group is traveling without its familiar enhancements of strings and brass this time, the lean format will permit unexpected twists and previews of unrecorded material. With the band’s reputation for experimentation and pursuit of the elusive moment, each show promises to be an unrepeatable event.

In its press release, Sigur Rós addressed the expectation of making an album and then performing its songs for the audience. “There was a time when things were the other way round, when we worked stuff out on the road, and trying to capture lightning in a bottle was a problem for the studio later on. This time, in addition to playing songs you know, we wanted to remember the seat-of-your-pants feeling.”

* Sigur Rós, 8:30 p.m., Sep. 30, Chicago Theatre, 175 N. State, Tickets $69.50-$79.50; ticketmaster.com.

Jeff Elbel is a local freelance writer.