Positioned between the busy pulse of ska and the slower certainty of reggae, rocksteady combined some of the strengths and attributes of both during its brief Jamaican run between 1966 and 1968. The less kinetic rhythms allowed singers to step to the fore, and the island's fascination with American R&B grew even more pronounced, resulting in a whole host of interesting Jamaican re-imaginings of American soul hits. This two-disc, 54-track set makes for a nice introduction to rocksteady, but it has a down side. Filled with productions by Duke Reid, Derrick Harriott, Sonia Pottinger and Joe Gibbs, it lacks anything from Clement Dodd's Studio One, which is a bit like not including anything from Stax Records on a vintage Southern soul collection. Still, the story of rocksteady does get told here, and sides like Alton Ellis' "Cry Tough," Stranger & Patsy's gorgeous "Down By the Trainline," the Ethiopians' "Train to Skaville" (which was all rocksteady and not ska at all), the Uniques' brilliant "My Conversation" and Desmond Dekker's "Israelites" are stone-cold classics no matter what the genre.