Apple today introduced its DRM-free, higher-quality digital music store in an update to the iTunes service, called iTunes Plus.

The new iTunes tier will feature music with no DRM protection technology and 256 kbps file sizes for $1.29 per track, compared to the DRM-protected 128 kbps files sold on the existing iTunes service for 99 cents per track.

iTunes users can replace any music previously purchased from the existing iTunes service with the new DRM-free/higher quality tracks by just paying the 30-cents difference, rather than repurchasing the whole track.

EMI Music Group is the only major label licensing music to the new iTunes Plus service. Apple is working on added additional indie label fare as well.