In addition to their use in the creation of masters, they were widely used for many purposes before magnetic tape recorders became common, and in the modern era they are used by dance music DJs. They were used in radio broadcasting to archive live broadcasts, pre-record local programming, delay network feeds for broadcast at a later time, and provide programming "from home" on the Armed Forces Radio Network. They were used extensively in Jamaica by sound system operators in the late 1940s and 1950s. Acetates were often used as "demos" of new recordings by artists and record labels. Some acetates are highly prized for their rarity, especially when they contain unpublished material.