Music Formats and DRM

How copy protection affects your purchase

Music downloads come in a variety of formats, called "codecs." MP3 is the most flexible format, since almost any portable music player will play an MP3 music file. However, most music download websites don't use (or are discouraged from using) the MP3 file format because MP3s aren't copy protected. Today, the majority of online music stores use the WMA format, which can be closely controlled by a copy-protection scheme called Digital Rights Management (DRM). Whenever you download a DRM-protected WMA music file, it will come with restrictions on how you can use that music. For example, some music services will restrict how many times you can burn a track to a disc. DRM also allows services to offer subscriptions whereby you "lease" music instead of owning it (which means that all the music you've leased disappears if you discontinue your subscription). Almost all MP3 players (except for iPods) can play songs in WMA format.

One issue that iTunes users in particular have had to contend with is the restrictions inherent in DRM-protected files. Until the spring of 2007, all of the iTunes catalog was made up completely of DRM-protected files. Apple's deal with major label EMI to offer DRM-free tracks for a slightly higher price changed all that, and iTunes users now have a selection of DRM-free tracks (dubbed iTunes Plus titles) available for purchase from EMI and several independent labels. Other major labels have been slow to catch on, however, at least with Apple. After facing increased competition from other sites with larger libraries of DRM-free songs, including Napster and fledgling service AmazonMP3, Apple quietly dropped the price of its DRM-free tracks to $.99 apiece (dropping the iTunes Plus name as well), bringing them in line with the rest of standard DRM-protected selections.

Even with these DRM-free options, iTunes users may still find that they don't have as much freedom to transfer their tracks between devices or applications as they'd like. iTunes uses a proprietary codec called AAC (Advanced Audio Coding) for all of its tracks. AAC songs can only be played on iPod music players and through the iTunes software on your computer. Even DRM-free AAC tracks still have some restrictions; while you can play the tracks on as many computers as you want, you still can't play the tracks in Windows Media Player or on a non-iPod player. To play a song you've purchased from iTunes on another player, you'd have to first convert it to the WMA or MP3 format with third-party software or burn it to a CD. The problem with buying Apple's AAC-coded songs is that you're buying into an uncertain future; to date, Apple has refused to license this technology to other manufacturers. iPods are popular now, but five or ten years down the road, the story could be different -- and if Apple doesn't soften its stance, that means you'll have little choice but to continue buying AAC-compatible Apple music players in the future, regardless of whether other devices are better.

Bit rates

Online music stores sell music in varying bit rates, which is roughly proportional to sound quality. The typical bit rate for most music downloads is 128 kbps, but some services go up to 160, 192 or even 320 kbps. However, sound quality is also affected by the quality of your music player, your headphones and/or your computer speakers. If you have audiophile-quality equipment (or ears), you're better off going with a service that offers at least a 192 kbps bit rate for music downloads.

Music downloads vs. music subscriptions

Some music download services are exactly that -- you pay a dollar or less for a song and download it to your computer. You now own that song, which you can burn to a CD or transfer to a portable music player. Depending on where you bought the song, there might be a limit to how many times you can copy the song to another computer or burn it to a CD.

Most online music services also offer a monthly music subscription that allows you to essentially "rent" music. Services like Rhapsody To Go and Napster To Go let you choose an unlimited amount of music from their catalogs, which you can listen to on your computer or download to a compatible MP3 player. If you cancel your subscription, however, you lose access to that music. Napster has a service that lets you purchase tracks without a subscription, though you can no longer stream entire songs online for free. Reviewers generally favor these music subscription services, which allow you to sample a wide variety of music at a relatively low cost, over à la carte services.