Polvo's Wikipedia page states that the group now disavows the "math-rock" categorization that Polvo earned from their first incarnation (1990-1998). Their new album, Siberia, is proof.
While 2009's In Prism was a recognizable bridge to their past, the band's signature off-kilter start/stop phrasing, angular and trebly guitar riffing, and subtle Eastern musical influences (see 1996 opus Exploded Drawing and 1998's equally excellent Shapes) take a back seat to straight-up '70s rock riffage on Siberia.
"Total Immersion" kicks off the album, with the Chapel Hill, N.C., quartet rocking out their best Crazy Horse. Singer/guitarists Ash Bowie and Dave Brylawski's guitar interplay has always been a mainstay of the band's sound. Here, they create tension between straight ahead rocking and the obtuse and trebly skronk that the band built their name on in the early '90s. In the end though, it's the former that prevails.
"Blues Is Loss" and album closer "Anchoress" contain the only easily recognizable ties to Polvo's past. And both highlight everything that made this band great in the first place.
Much of the rest of Siberia tends to lean toward the warm tones of '70s AM guitar that wouldn't be out of place on a Big Star album. It's not bad, per se; but it's not necessarily the same Polvo that released 1992's Cor-Crane Secret, which gained them the math-rock god status in the first place.
Toward the end of "Changed," Bowie sings, "I have changed/ You have, too/ I have changed/ I had to." Regardless of their typically cryptic lyrics, it's hard not to read this as a self-referential explanation for the Polvo of 2013, and that's at least respectable.