For a band that hasn’t released a new full-length since 2010, Black Mountain has crafted an unshakable aura of myth and mystery around its next move, which makes IV well worth the wait. As usual, the shadow-andlight vocal interplay between Stephen McBean and Amber Webber is the music’s lifeblood, but what’s clear from the hypnotic opening track, “Mothers of the Sun”—a roomy eight-and-a-half minutes of hard riffs, languid beats and stretched-out atmospherics—is how far the band has progressed beyond the stoner rock and tribal electro-boogie of 2005’s self-titled debut. While the familiar ‘70s tropes of Zeppelin, Sabbath, Floyd and even Kraftwerk and Can still linger—right down to the Hipgnosis-style cover art, designed by keyboardist Jeremy Schmidt—the songs on IV stand on their own as part of a carefully thought-out whole. You can feel the work that went into the Bowie-ish “Cemetery Breeding” (which echoes the whistling synth melody of “Ashes to Ashes”), or the broodingly seductive “Defector,” or the tightly wound punk workout “Florian Saucer Attack” (a prime vehicle for Webber, as is the wrenching folk dirge “Line Them All Up”). If “classic” rock is all about creating new worlds to get lost in, then this one qualifies.