Lewis was approached by Ace Tone president and founder Ikutaro Kakehashi, who wanted to know how Lewis had achieved the sounds using the Ace Tone machine. In 1972, Kakehashi formed the Roland Corporation, and hired Lewis to help design drum machines. By the late 1970s, microprocessors were appearing in instruments such as the Roland MC-8 Microcomposer, and Kakehashi realized they could be used to program drum machines. In 1978, Roland released the CompuRhythm CR-78, the first drum machine with which users could write, save, and replay their own patterns.