Thee Silver Mt. Zion is one of those rare groups that manage to sound warmly familiar while still reveling in the sublimely unexpected. The fact that such a dynamic comes from members of post-rockers Godspeed You! Black Emperor is itself a testament to the inherent connection between trial and tradition. But what's truly remarkable about Thee Silver Mt. Zion (or any of the other monikers that these guys release CDs under) is how they create a paradigm shift that feels both organic and customary — even as the band changes gears from somber, sedate soundscapes to frenetic, balls-out rave-ups. This transformative character has emerged over the band's most recent releases (like the new 13 Blues for Thirteen Moons), but it sounds like it was there all along, just waiting to be excavated.