Sony Music Entertainment has agreed to allow MP3 store eMusic access to its back catalogue. It's the first of the four major labels to strike a deal with the website.

However, there's a catch. Only tracks more than 2 years old will be added. That includes artists like Michael Jackson, Bruce Springsteen and Billy Joel, but not Kings of Leon, Beyonce or Leona Lewis.

eMusic offers a subscription service a little different to most. £10.99 per month gets you 30 MP3 downloads which you can keep. £11.99 will up that to 50 MP3 downloads. Until now however, the only catalogue available has been from independent labels.

Adding Sony to the mix makes the offering more attractive, however the company will be raising prices and reducing the number of downloads as part of the deal. That could upset some users who aren't necessarily interested in the major's catalogue.

Elsewhere, commenters have also suggested that this move might be eMusic's response to competition from Spotify and, who offer unlimited free streaming of tracks in exchange for occasional adverts.