The Apple rumor du jour is that Sony Music Entertainment will license DRM-free tracks to iTunes, under the iTunes Plus program. The speculation began on Apple blog, which provides very little information other than hinting its more than just a hunch.

A Sony Music spokesperson did immediately respond to requests for comment.

To date, EMI Music Group is the only major label licensing DRM-free tracks to iTunes. The others license DRM-free to other services, notably, but have resisted doing the same in iTunes.

Reasons vary. In some cases, labels want to empower iTunes competitors with DRM-free files so they can sell iPod-compatible music. In other cases, labels say there's no reason to sell sans DRM on iTunes because protected iTunes files work just fine on the iPod.

The iTunes Plus program features DRM-free files at a higher bitrate (256 kbps vs. 128). At launch in 2007, iTunes Plus files were priced higher, at $1.29, but soon after Apple lowered the price back to 99 cents.