For only their second studio release after 13 years of regular gigging, Boston ensemble Club d’Elf unloaded a whopper, an honest-to-goodness double album, or rather, two full-length CDs packaged together, each highlighting one of the band’s prevailing styles. The goofy title Electric Moroccoland belies its seriously accomplished fusion of jazz, electronics, funk and space-rock with Moroccan folk music, particularly gnawa. So Below features a similar musical approach, but the earthy, organic Moroccan element is more or less replaced by a sometimes-snarling, circular jam style heavily informed by the electro-voodoo-funk of Miles Davis’ mid-’70s recordings.

Club d’Elf are an ensemble of rotating membership; questing spirit and chief songwriter Mike Rivard is the ringleader, bringing together varying combos of collaborators. The biggest names on this release include John Medeski, DJ Logic and long-time David Bowie guitarist Reeves Gabrels, but the focus is on no particular performance or even composition. It’s about the layering of musical voices (a dozen or more musicians are credited on some of the particularly busy tracks), held together by the gravitational force of Rivard’s meditative but melodic basslines and rich percussion beds that might include rock-style drums, dumbeck, handclaps, electronic beats and more. (Eric Kerr’s literate, tenacious drumming is key to the Morrocoland disc.)

Cultures and centuries mix and match in a way that never comes off as academic. Gnawa heavyweight Hassan Hakmoun is enlisted to sing lead vocals in Moroccan on a revelatory transfiguration of Cream’s “Sunshine of Your Love,” while “End of Firpo” could easily pass as a particularly outré nugget of late-’90s intelligent drum and bass, with Medeski’s dreamy Rhodes chords mixing with the great Brahim Fribgane’s ringing oud lines and electronic breakbeats by Matt Kilmer.

The whole enterprise, So Below in particular, is steeped in a Millennial aesthetic. On occasion it sounds dated—the repeated “Are you ready for this?” vocal sample in “Bendir Done That” might have sprung from a time capsule—but this lengthy set offers a healthy and satisfying sample of the free-spirited, cross-genre innovation this uncompromising combo have perfected.