Chances are that if you see the word “angular” in a music article, a mention of the band Polvo won’t be far behind. No one can exactly tell you what “angular” means in relation to music, but Polvo’s pitchbending licks and odd melodic hooks are about as perfect an impression as you’re likely to get. In other words, if you like “angular” music, you probably have Polvo or something like them in your collection; no surprise, then, that they’re a cult favourite that pops to most people’s minds if you ask them what math rock is.

Ash Bowie, the lead guitarist of the group, had joined Helium not long before Polvo’s final album and tour, but by 1998 both his projects were all but dead. Fast forward to 2000, when a wave of Helium alumni material came out. Mary Timony’s Mountains was the logical reconfiguration of The Magic City as a solo album; meanwhile, Bowie took out a bunch of old demo tapes and reworked them. The end result was released under the name Libraness, and it sounds like what you’d expect from one of the former songwriters behind Polvo: lots of bendy guitars and runaway melodies in odd time signatures. But just like Timony’s album, Yesterday And Tomorrow’s Shells was a more introspective and toned-down affair; waves of fuzz and distortion dull the edges off many of the more vicious tracks. All in all, a worthy addition to the canon of angularity—and perhaps the last we’ll ever hear from Ash Bowie, as he’s pulled a Kevin Shields and largely disappeared from the scene.