In case you didn't know, these are the big boys who, for the most part, try to tell you what to listen to. Although independents account for 28 per cent of the market, the music industry today is still dominated by 'the Big Four' record companies.Universal Music GroupChairman and CEO Doug Morris presides over the largest record company in the world. Taken together, its labels such as Island, Polydor and Mercury account for a 25.5 per cent share in the global market. UMG itself is a subsidiary of Vivendi, the French media conglomerate.Sony BMGThe result of a 50/50 joint venture between Sony Music Entertainment (part of Sony) and BMG Entertainment (part of Bertelsmann). Subsidiary labels include Arista, Columbia, Epic, J Records and RCA.Warner Music GroupSubsidiary labels include Elektra and Atlantic. A merger with EMI looked likely until the latter was bought out by private equity firm Terra Firma.EMIThe only British company in the pack, formed in 1931. Now run by Terra Firma boss Guy Hands; recently parted company with both Paul McCartney and Radiohead.