EMI has confirmed that the company's move to sell DRM-free tracks through iTunes has been a significant success.

Speaking at a US music industry event, digital senior vice president Lauren Berkowitz said: "The initial results of DRM-free music are good."

EMI began selling its music in high-quality DRM-free format last month. It's unrestricted catalogue is now available for sale from 7Digital and Apple's iTunes. In future, EMI will sell DRM-free music through Amazon and PassAlong Networks.

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Berkowitz said that initial success with DRM-free songs seems set to boost sales of digital albums, as well as songs. She confirmed that sales of the legendary Pink Floyd album, Dark Side of the Moon had increased since it shipped DRM-free - these are up 350 percent.

The other three major labels: Universal, Warner and Sony/BMG are reportedly studying the results of EMI's experiment closely. Those labels still favour rights-restriction in an attempt to protect their content, but market pressure may force them to emulate EMI and join Apple's iTunes Plus service.

Labels in the independent sector have been cheerfully embracing DRM-free music for many years now, and claim their strategy has been successful.