As the supply of previously unheard tunes in the jump blues and more traditional R&B genres began to dry up in the late 1950s, Jamaican producers began recording their own version of the genres with local artists. These recordings were initially made to be played on "soft wax" (a lacquer on metal disc acetate later to become known as a "dub plate"), but as demand for them grew eventually sometime in the second half of 1959 (believed by most to be in the last quarter) producers such as Coxsone Dodd and Duke Reid began to issue these recording on 45rpm 7-inch discs. At this point, the style was a direct copy of the American "shuffle blues" style, but within two or three years it had morphed into the more familiar ska style with the off-beat guitar chop that could be heard in some of the more uptempo late-1950s American rhythm and blues recordings such as Domino's "Be My Guest" and Barbie Gaye's "My Boy Lollypop", both of which were popular on Jamaican sound systems of the late 1950s. Domino's rhythm, accentuating the offbeat, was a particular influence.