As genres bleed, implode, breed and keep going, there’s a new pack of Stateside metal shape-shifters, a loosely connected group of musicians that includes, among others, Pyramids’ R. Loren, the guys in Locrian, and, of course, Jenks Miller. We last heard Miller via the folky Americana of Mount Moriah, though he’s better known for Horseback’s Southern-tinged, noirish black metal drone. The guy’s a fascinating composer, something more apparent than ever on The Gorgon Tongue, a double CD that pairs Horseback’s 2007 out-of-print VHF-ready debut Impale Golden Horn with the harsher post-Invisible Mountain blackened atmospherics of the cassette-only Forbidden Planet. The Impale portion features some of Horseback’s most patient, painterly, and straight-up pretty music. Listening to it together with the bleaker new material does for Miller what Heart Ache & Dethroned did for another brilliant metal-based composer, Justin Broadrick: It allows you to trace the evolution of a singular sensibility, offering overlaps and divergences, suggesting future wrinkles and pathways. The gentle, 8-minute “Blood Fountain” emerges after almost 40 minutes of cascading, softly consuming Richard Youngs-esque drone. I’d call it the quiet after the storm, but here even the storm’s pretty relaxing. Mount Moriah’s Heather McEntire joins him on the track. Take a look at its Jon Mackey-directed video.