Amazon.com has added songs from Warner Music Group to the range it sells as MP3 files without DRM (digital rights management).
The online retailer launched its music download service in September and now offers 2.9 million songs without copy prevention technology, including tracks from Warner, EMI, Universal and 33,000 independent record labels - although it has still not won over Sony BMG, the only one of the music majors still insisting on the use of DRM.
Warner said it also planned to offer album bundles including exclusive tracks through the Amazon service.
The move is a blow to Apple's iTunes Store, which has only persuaded EMI and a handful of independent labels to let it offer their tracks in the DRM-free iTunes Plus format it launched in May. The rest of the songs available through iTunes come with digital limitations on where they can be played, or how many times they can be burned to a CD.
Three formats dominate the market for online music sales: MP3 and AAC, which are both open formats, and WMA, a proprietary format owned by Microsoft.
MP3 files do not include provision for DRM: music recorded in that format will play on most digital music players, many mobile phones, and in software readily available for all the major operating systems, including Windows, Mac OS X and Linux, opening up a huge potential market to Amazon and to other online music stores such as eMusic dealing in unprotected MP3 files.
AAC is the format Apple chose for its iTunes Store. Most of the 6 million tracks in its catalogue come wrapped in a proprietary DRM layer called FairPlay, although EMI and independents such as Sub Pop, Nettwerk, IODA and The Orchard also allow it to offer higher quality AAC recordings without DRM. The DRM-encumbered tracks will play on authorised iPods, iPhones, PCs and Macs - but won't play on digital music players from other vendors. Unprotected AAC files will also play on many mobile phones, PCs running Linux with the appropriate software, and even Microsoft's Zune digital music player.
WMA files without DRM will play on PC or Macs using Windows Media Player, and some phones and digital music players - although typically not on the same ones that play AAC files. Microsoft has also introduced a range of DRM systems enabling online stores to sell locked WMA files - and later abandoned some of them, leaving a certain amount of confusion and doubt about whether devices and songs branded 'PlaysForSure' really will play for sure.
Industry executives expect initiatives such as iTunes Plus and Amazon MP3, which remove the DRM locks placed on music downloads by an earlier generation of music services, will encourage consumers to buy more music.
Warner believes that giving consumers the assurance that the music they purchase can be played on any device they own will only encourage more sales of music.
It may also persuade music-buyers to look at other brands of digital music player such as the Zune range from Microsoft, ending Apple's dominance of that market segment.
With the locks off the music, Apple also faces the prospect of a price war with Amazon, which offers 1 million of its MP3 tracks for just $0.89, compared to the $0.99 Apple charges for all its tracks. Before the launch of Amazon MP3, Apple also charged a $0.30 premium for tracks in the iTunes Plus format, which is recorded at a higher quality than the DRM-encumbered versions. Other Amazon tracks sell for $0.99.