For more than two decades, packs of profiling, rhyming hopefuls have stood 24-7 in King Jammy’s sun-baked Kingston yard, each one praying to be called into an adjoining recording studio and emerge as the next Shabba Ranks. Jammy has never been Jamaica’s sole route for reggae talent, but he did produce Wayne Smith’s “Sleng Teng,” the 1985 tune that launched digitalized reggae (a/k/a dancehall) and spawned countless other computer-driven hits, many riding the same catchy instrumental (also dubbed “Sleng Teng”) Smith had discovered while fiddling with a battery-powered Casio keyboard. After failing repeatedly to “get it back,” as Smith recounts in the DVD accompanying this first of an ambitious Jammy re-release series, he finally pushed the right button and ran to the King, who filled out the Casio’s spare, tinny track from his studio mixing board. A quicker, edgier dancehall style has since broken through the glass ceiling that kept “Sleng Teng,” Johnny Osbourne’s “Water Pumping,” Leroy Smart’s “Let Off Supum,” Nitty Gritty’s sublime “Run Down the World,” Super Black’s “Deh Wid You,” and almost all this set’s treasures buried in the international underground. Yet variations on Jammy’s ’80s riddims still motor today’s boomshots, which rarely match the musical delirium of these originals.