When it comes to the Boredoms, it's best to expect the unexpected. After a drought of new material spawned rumors that the long-running Japanese band had broken up (or at least changed its name to Vredoms), in September it suddenly released Seadrum/House of Sun (Warner Music Japan), its first album in four years. The band's members can be similarly mercurial when it comes to side projects. On earlier albums OOIOO--led by Boredoms drummer Yoshimi--experimented with catchy Krautrock grooves, but on the new Kila Kila Kila (Thrill Jockey) it opts for a more amorphous and dreamy approach. "On Mani" uses a pummeling rhythm to deliver string, guitar, and trumpet variations on the theme of an imaginary western, but most of the other songs shape-shift and aren't so tidily genre-bound. Whether it's the brief organ noodling on the title track or the way the shuffling "Northern Lights" broadly rearranges a terse melody line, the music rarely stands still--Yoshimi herself switches between vocals, keyboards, and percussion on the album (and is skilled on many other instruments). But rarely standing still doesn't always mean getting somewhere: on many of the pieces the quartet sounds content to see how much they can transform the color, tone, and heft of bits of musical material. To the band's credit, the steady alterations arrive in a seamless flow; unless you're paying close attention you might not even notice that something's changed. Given Yoshimi's experimental instincts, what they'll do live is anyone's guess. Pit Er Pat and Voltage open. Tuesday 11/9, 9:30 PM, Empty Bottle, 1035 N. Western, 773-276-3600 or 800-594-8499, $12.