In the two years that followed their surprise alt-rap crossover smash debut Reachin’ (A New Refutation of Time and Space), Digable Planets went from Grammy-winning phenoms to a cast-aside casualty of a baffled record industry. But the Difficult Second Album that led them there has proven to be their most-beloved work: Blowout Comb emerged as a cult critical favorite that a long-tail enthusiasm would eventually exonerate in the wake of the label’s antipathy. Part of the challenge — and the reward — came from the beats: the shift from straight-up Blue Note-worthy jazz-hop to a more elaborate fusion of samples and live instrumentation meant their sound could take hip-hop production’s trans-generational source-updating retrofuturism into an even deeper space-time refutation. (A lot of Golden Era beatmakers riffed off Roy Ayers and Bobbi Humphrey as formative ’70s icons; “Borough Check” and “The Art of Easing” make them sound like two of the most important artists of the ’90s.) Since the beats often grow deep and heavy enough to subsume the MCs’ voices into a half-audible, impressionistic component of the music — a decision made by design in an effort to draw in curious listeners itching to fill in the blanks through repeat listens — that brings Butterfly, Doodlebug, and Ladybug Mecca into a context where their deceptively calm-and-collected flows and timbres sink in before their allusive-yet-clearspoken lyrics do. So by the time you catch on to their perspectives — 5 Percenters just as concerned with the benefits of collective joy as they were with struggle, invoking their elders’ experiences and ideas and lyrics with the determination of people ready to win an unfinished fight — it feels like a revelation inside a revelation.