Apple has u-turned on its potentially expensive all-or-nothing policy of making an iTunes user upgrade their entire music library to the DRM-free iTunes Plus format.

Up to now, iTunes users had to shell out a lump sum to upgrade all their music tracks and videos, but it can now be done on a track, album or video basis.

Apple, slow to go DRM-free, charges around a third of the price of a song or album to upgrade the track to the higher quality DRM-free offering.

The announcement that iTunes was going DRM-free was made by Phil Schiller during his keynote speech at January's Macworld event in the US.