Supergroup is an iffy word to throw around when you’re talking about a bunch of dudes whose main bands are hardly household names in the first place, but to fans of boundary-pushing underground metal Twilight more than qualifies. The current incarnation is a six-piece that includes three members from the group’s 2005 debut, Chicagoan Blake Judd (Nachtmystium) and out-of-towners Neill Jameson (Krieg) and Jef Whitehead (aka Wrest of Leviathan), and adds three new guys: Aaron Turner of the late Isis and two more Chicagoans, Sanford Parker of Minsk and Stavros “Steve” Giannopoulos of the Atlas Moth (see Best Mustache in a Local Band). Because black-metal musicians make up half the lineup, black metal is a big part of Twilight’s new second album, Monument to Time End (Southern Lord), but it also incorporates the heaviness of doom, the complicated structures of prog, and droning soundscapes that have little in common with any kind of rock music. (It’s a testament to how far out the record gets that Chicago expat Robert Lowe makes an appearance in Lichens mode.) Monument is as beautiful as it is brutal, at least if you don’t find Judd’s strangled, nightmarish vocals off-putting—it’s a fantastic example of what can happen when a bunch of innovators get together and all but dare themselves to top the great work they’ve already done.