This spring I’ve hunt-and-pecked a lot of words in this space about Digital Rights Management (DRM). As you’ll remember, DRM is secret code added to digital media (software, video, and music) to prevent folks who didn’t purchase the media from being able to use it. DRM is attached to most commercial software, some commercial movie DVDs, and, until this week, all music sold on Apple’s online iTunes Store.

Awhile back Apple and major music distributor EMI announced a plan to sell DRM-free music on iTunes. This Wednesday, the plan went into effect, with the release of version 7.2 of the iTunes jukebox software, and major changes at Apple’s online store. Apple is calling the new music offerings “iTunes Plus”.

iTunes Plus songs are in the same AAC (Advanced Audio Codec) format used previously, minus the DRM code. Think of AAC as “MP4”, as it is the audio subset of the MPEG-4 industry media standard. Besides being DRM-free, iTunes Plus songs are of higher quality, encoded at 256 kbps (kilobits per second) instead of the previous 128 kbps. In keeping with my golden rule of digital media – higher quality equals bigger file size – the iTunes Plus songs are roughly twice the file size (7 MB versus 3.5 MB for a 3.5 minute song) of their predecessors. AAC-encoded music isn’t only for iPods. Other portable music players, even Microsoft’s Zune, have warmed to the AAC format.

Individual iTunes Plus songs cost $1.29, up 30 cents from the DRM-laden variety. After installing iTunes 7.2, the software will ask you if you want to “upgrade” your previously purchased songs to iTunes Plus for 30 cents per song. As iTunes knows (how do it know?) which songs you’ve already purchased, the procedure is simple and painless.

So, is iTunes Plus worth the extra third of a buck? That depends. If you’re an audiophile with high-end equipment, you’ll enjoy the reported noticeable improvement in sound quality. If you’re just using an iPod with its admittedly non-audiophile provided earbuds, you might not be able to tell much difference. If you don’t have much storage space (you should get more) or you don’t have much internet bandwidth (you should get more), the increased file sizes might be an issue.

Saying goodbye to DRM is a big plus in iTunes Plus. No more worries about “five authorized computers”, or whether the music can be played on non-iPods. Ain’t progress grand?