Though it has, until now, enjoyed only a cult following in the US, rocksteady has many fierce devotees worldwide. And for good reason: as the precursor of roots reggae and the successor to ska, rocksteady presaged dancehall more than any other Jamaican music. The cavernous basslines of roots and dub had yet to enter the scene when these 22 tracks were recorded in the late 1960s. Instead, skeletal percussion, lithe organ chords and soulful vocals are at the center of the mix. Derrick Morgan, who would go on to a long roots career, appears on nine tracks here, his wavering voice making a powerful impression. The lineaments of reggae have always been about the dialectic between the celebratory and the mournful, and tracks like “Let Him Go” by The Viceroys exemplify that wonderful aspect of rocksteady.