Apple will begin selling EMI’s entire music catalogue on iTunes at higher quality 256 kbps AAC encoding, without DRM restriction starting in May. However, music fans will have to pay more for the privilege of DRM-free music.

The higher-quality music will be sold on iTunes for 99p a track. Customers will still be able to buy DRM-protected EMI music at the existing lower bit-rate of 128 kbps for the original price of 79p.

iTunes customers who already own EMI produced music will be able to upgrade every track the higher quality DRM-free versions for just 20 pence a song, confirmed Apple.

The news follows Apple CEO Steve Jobs open letter in which he made his feelings known about the requirements of the big four music labels to protect the music iTunes sells with digital rights management. Speaking at a press conference in London today, Jobs said: “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”.

EMI is emphasizing the higher quality of the recordings. Eric Nicoli, CEO of EMI Group said: “EMI and iTunes are once again teaming up to move the digital music industry forward by giving music fans higher quality audio that is virtually indistinguishable from the original recordings, with no usage restrictions on the music they love from their favourite artists”.

More news to follow.