From hip hop to reggaeton to bhangra, the autonomous bass-and-drum grooves providing the foundation for global dance beats follow precedents set by Jamaican dancehall rhythms, whose earliest manifestations reveal aesthetic roots in the brief but pivotal period of stylistic innovation glossed as rocksteady. While often represented as little more than a transitional style between ska and reggae, due to the “essential Americanness” that such researchers as Lloyd Bradley hear in its soul-influenced vocals, rocksteady looms large in oral-historical accounts of prominent musicians, who place the emergence of the foregrounded, often percussive electric basslines and the one-drop drum-set conception—which Kenneth Bilby considers fundamental to the “re-indigenization” of the music—firmly within its seminal developmental ambit. In this paper, I draw upon artist interviews, ethnographic field research, and musicological analysis to cast new light upon the development of rocksteady’s startlingly original bass conceptions, which abandoned the walking basslines of African American jazz and boogie-woogie, in favor of locally conceived paradigms evincing noteworthy affinities to roots-drumming traditions like nyabinghi, while owing surprisingly little to the Motown/Stax-era soul models avowedly embraced by the musicians. As I demonstrate, from the time of their appropriation by the Muscle Shoals production team in the States—predating reggae’s rise to international prominence with Bob Marley’s “I Shot the Sheriff” or Jimmy Cliff’s “Harder They Come” —rocksteady rhythms helped set in motion cycles of cross-fertilization blurring the boundaries between local and global, national and international, and ultimately leaving a distinctive Jamaican imprint upon cosmopolitan dance culture worldwide.