The disc jockey, or more commonly the DJ is an entertainer who takes care of the music played in a room, often a disco or club, selecting (depending on the tastes of the public, of the opportunities, but also of his personal style) songs Various musical through a sound system that the environment itself is fitted and it is connected to the console (or disk-console), through which, with the technique of mixing (in English mix), you can join with sequence more tracks from different sound recordings, such as the vinyl disk or compact disc, so as to obtain a single stream of music that is pleasing to the listener. Some DJ coincides with the birth of the first experiments in radio, when the pioneers of radio transmissions linked to the gramophones trasmettitori.Ciò notwithstanding, the real beginning of the DJ came with the opening of the first clubs in France during the Nazi rule. During this period arose the first few discotheques where they were popular jazz and blues records from the new continent despite the regime prohibiting the dissemination of works by US record companies. Of course he wanted someone employed to select such discs: that someone will soon become the "DJ" with the release of the closet disco and export to America in the sixties where it will be coined the term DJ (literally "disc jockey"). At first, the task of the DJ was simply to put one after the other discs (purchased from local) and make alerts with the microphone. The DJ then felt a salary equal to or less than that of a bartender. In the '70s came the Saturday Night Fever (Saturday Night Fever), and disco music. Along with disco, DJ gained increasing prestige, becoming the architect of a successful event and the good name of a local. Next they came the times of the Loft and the disco became a place of love for music where people came to get carried away by the atmosphere created by the DJ. The first stars were born the first of which was for sure Dave Mancuso inspiring a generation of patrons of his loft, launching DJs as Larryn Levan, Kenny Carpenter, Frankye Knuckles, Nicky Siano, Francois Kevorkian and Larry Heard. In Italy in 1975 Miki Ciak of Bologna was the first to let the public know the American musical genre with his great technical ability in mixing comparable only to the best DJs from overseas. In fact, the Americans were the inventors of the house music movement that called the "the" in one gigantic line of electronic music, produced by the DJ himself. Since then, the DJ took over the role of sound experimenter and the tightrope walker of the mix with the introduction of the mix "in joke" technique to to match perfectly the lines of time of two disks in sync (beats expressed in bpm, or beats per minute). In the mid-80s came Carl Coks who was one of the few to use in an evening three meals, two to mix and one to create effects, or enter in the selection of the versions "a cappella" songs to create real and its remix live.