From May, iTunes customers will be able to download tracks from EMI artists without usage restrictions that limit the types of devices or number of computers that purchased songs can be played on.

The EMI tracks will be available for $1.29 per song. In addition, iTunes customers will be able to upgrade their entire library of all previously purchased EMI content to the higher quality DRM-free versions for $0.30 a song.

iTunes said that it will continue to offer its entire catalog, currently over five million songs, in the same versions as today – 128 kbps AAC encoding with DRM – at the same price of 99 cents per song, alongside DRM-free higher quality versions when available.

We are going to give iTunes customers a choice – the current versions of our songs for the same 99 cent price, or new DRM-free versions of the same songs with even higher audio quality and the security of interoperability for just 30 cents more, said Steve Jobs, Apple’s CEO. We think our customers are going to love this, and we expect to offer more than half of the songs on iTunes in DRM-free versions by the end of this year.