In hindsight I probably dismissed Horseback’s Invisible Mountain a bit too easily. I gave it a respectable mark, but haven’t revisited the album until now, thinking smugly that I had it pegged. Certainly, the band (masterminded by multi-instrumentalist Jenks Miller) fit neatly on the cutting edge of psychedelically-tinged US ‘sort-of-metal’ alongside Earth or Culted, and so forth. But this is a project with a distinctive and multifaceted vision, and with Half Blood, Miller’s first full release written specifically for Relapse, that vision that is honed further. This is an impressive work, at times hypnotic, at times abrasive, and at times addictive. Always, though, it is surprisingly fun to listen to.

So, in some respects this is very similar to The Invisible Mountain (there’s been another Relapse re-release in between, which I confess I haven’t heard). The overall format is typical of Horseback, making heavy use of minimalist vistas of laid-back Americana given a subtle metallic sheen, but also becoming more abstract and freaky as the track listing progresses. The songs appear more compact- there are seven of them, with shortened average lengths. There are a couple of 3-4 minute numbers here, even. This, perhaps, reflects a desire for a little more diversity and experimentation. While the last three form a suite, other short pieces here serve as standalone forays, pursuing curious new directions to the intrigue of the listener. Inheritance, for example, is a cunningly-worked dabble in electronic abrasion; a hissing and buzzing crescendo that gives way to gentle piano chords.

And so opener Mithras is an easily-recognised sibling to Invokation, the track that introduced Invisible Mountain. A head-nodding bass guitar groove and thudding backbeat is given neat, subtle colouring by delicate electric piano tinkering. The latter, in fact, gives the sound something of Miles Davis’s fusion classic Bitches Brew- a likeness which at first seems fleeting but, as we shall see, comes back stronger later on. This gentle backdrop is joined incongruously by hissing, rasping black metal vocals. An odd combination, but very much the Horseback vibe. Arjuna takes a very similar approach later on in the record; almost like a reprise, with a rare instance of fuzzed-out lead soloing adding an instrumental focal point. Both these tracks feature the kind of laid-back, windingly repeated melodic fragments that, to my mind, are one of Horseback’s trademarks, and which give the sound a lot of warmth. In this regard the most obvious highpoint is Ahriman, which is built around a gorgeous blues riff, where again the keys (this time an organ) are employed to add tonal colour.

The closing statement is the Hallucigenia triology, where the sound suddenly becomes strikingly more enigmatic. The unifying theme here is fuzz. I is a miasma of crackling static and Xasthurian vocal rasp, juxtaposed surreally with the gentle guitar flourishes that waft in the background. II pulsates around one note; a restrained build into the closing coup de grace, a twelve minute drone jam. And this is where that Bitches Brew likeness comes back even stronger. The backdrop is a hypnotic open-harmony haze, like a hundred of those cool little drone machines used in Indian music, over which the electric piano resurfaces, meandering through subtly-coloured tonalities, interacting sparingly and reticently with effects-laden guitar noodles. The effect is restrained, subtle, and quite captivating to listen to. In short, this is an important record for those interested in esoteric post-metal. It is diverse and experimental, plucking out wisely-chosen influences and paying homage to them with skil and subtlety.