One of the biggest announcements at Macworld 2009 was that Apple would be selling all its music DRM-free by the middle of the year.

Apple describes iTunes Plus as follows:

Apple’s DRM-free format with higher-quality 256 kbps AAC encoding for audio quality virtually indistinguishable from the original recordings.

To the average consumer even this description doesn’t mean much.

DRM Free?

Many of you may be asking what exactly DRM is in the first place. DRM which stands for Digital Rights Management prevents songs purchased on the iTunes Store being played on any other music player that isn’t an iPod. Additionally iTunes songs with DRM can only be on five computers at one time and can only be burnt to a CD seven times in an “unchanged playlist”.

iTunes Plus songs lose all those restrictions as well as receiving double the sound quality. This means you can move your iTunes Plus songs onto any digital music player, give them to all your friends and burn unlimited CDs.

File Format

Apple uses a file format called AAC, despite many claiming that it is a proprietary format it is not. AAC is simply an alternative to the MP3 format and is represented with the .m4a file extension for DRM-free and .m4p for DRM’d files. The problem with AAC is that some digital music players are unable to play it. Thankfully iTunes allows you to convert any iTunes Plus song to a normal MP3 file.

To help you along here are a few popular non-Apple products that support DRM-free AAC files: Nintendo Wii, Playstation 3, Sony Ericsson Walkman phones, Sony PSP, Creative Zen and Archos 605 WiFi.

Account Information

There is one downside to purchasing iTunes Plus songs, despite having no DRM they still contain your email address which is embedded into the file when it is download to your computer. Not a problem unless you wish to share your file around the world.

Upgrading to iTunes Plus

The iTunes Store has been in operation since 2003 which means many of you have 5 years worth of music which does contain DRM. Apple is offering you the chance to remove the DRM from all of these files for 30¢ (£0.20) a pop.

Unfortunately Apple only offers the opportunity to pay and convert all your music at once.

How do I know?

Apple announced that it would be slowly moving all of the iTunes Store over to iTunes Plus, so it is possible that some songs will still contain DRM on the Store for the next few weeks.

When buying from the iTunes Store DRM-free songs contain a plus icon next to the buy button.