Vinyl records were predominantly recorded in speeds of 33 or 45 rpm. They supplanmted the 78 rpm record, which had been made of a rather brittle urea-formaldehyde resin. Sizes were 7 and 12 inches diameter. A 45 rpm 7 inch was called an EP or single, because it held a single song on each side. A 33 rpm 12 inch was is an LP or long-playing? record, with 5 or 6 songs on each side. In the 1980s, vinyl records were gradually replaced in mainstream music consumer markets with the compact disc (CD). Vinyl records continue to be manufactured and sold today, although it is considered to be a [niche market]? comprised of audiophile?s, collector?s, and disc jockeys (DJs).