Having been around for many years and fourteen albums, Zu release Carboniferous, their debut on Ipecac, home of Isis, various Mike Patton projects, and many more, thus bringing them into a sphere of orbit that will likely touch that of experimentally-minded metal fans. Hell, among the various guests featured here is King Buzzo of the Melvins, which tells you something about the band’s approach.

Carboniferous presents a rhythmically-advanced, sludgily grooving rock base; a deep and antisocial, fuzzy sound, which is occasionally adorned by jazzily technical flourishes. Whenever I review projects such as this, with heavy roots in jazz, I seem to be drawn towards Meshuggah references, and this is no exception. Time feels twist and turn, and much of the music’s intensity comes from its off-kilter rhythmic riff ideas, as with on records such as Nothing. But the sound here is less metallically intense, and more sullenly downbeat. And striding above the dark and rumbling rhythm section is not a vocalist, but a saxophonist, making this eminently comparable to those other loons on the fringes of metal, Yakuza. Don’t be fooled into expecting a frenetic Zorn-style woodwind assault from Luca Mai, however. His performance (on the baritone, rather than the alto) is far more minimalist, blending in to the overall timbre rather than squalling above it.

Perhaps the best comparisons are less with metal bands and more with those on the hipper ends of the jazz scene. There’s a definite kinship with the British outfit Acoustic Ladyland, for example; both have an enthusiasm for obnoxiously growling rhythm section chuggers nevertheless blessed with insistent immediacy, and both see the saxophone as a more than adequate replacement for vocal chords when it comes to musical hooks.

As far as highlights go, perhaps foremost is spectacular opener, Ostia, which sets a high bar that I don’t feel the rest of it can quite match. A squelching, insolently simple electronic line forms a platform for surprisingly tasteful percussive pyrothechnics, jubilantly ugly woodwind squawking, post-punkish synth interjections, and hammering arpeggiated flashes. Some tracks reveal are surprisingly dramatic depth to the band’s sound. Obsidian is immense; a hostile, mocking electro-acoustic thud reminiscent, bizarrely, of Ajattara’s Noitumaa alternates with rich, almost epic passages in which double-barrelled synth crashes in like a tidal wave.

This is immensely cool, although likely an acquired taste. Patton devotees, for example, should lap it up, not just for the man himself’s input (as a guest on a couple of tracks, providing familiarly rabid vocal splutterings), but also for the intelligent but charismatic marrying of avant-garde ideas to immensely listenable music. A definite hit.