Online Music: Turn on & Tune In

If you're a music fan, there's no better source than the Internet. A high-speed connection and a good set of speakers or headphones turn your computer into a digital jukebox. With online music services, you can listen to commercial-free channels or choose from your favorite artists and songs; others allow you to burn songs to a CD or load them on a portable player for mobile listening.

As the list of online music services continues to grow, you will undoubtedly wonder which is best. Unfortunately, there's no easy answer. The right one for you depends on your musical tastes and how you like to listen to music.

Music services break down into two basic types: subscription and non-subscription. With non-subscription services, you pay to download individual songs or an entire album. Apple's iTunes Music Store has sold well over a billion songs at US $.99.

With subscription services you pay a monthly fee to access libraries of a million or more songs. But you don't actually own the songs. Once you end your subscription, the music stops, unless you've actually purchased individual songs. Most subscription services also charge an additional fee for their "To-Go" service, which let's you load songs on a portable device, like an iPod. When evaluating a service, consider your listening habits.

Perhaps the most important question is whether the service has the music you want. It doesn't matter what it costs if you don't like the tunes. While most services have large libraries, it's quality, not quantity that matters. For instance eMusic specializes in non-mainstream artists--terrific if you like Mingus, but not if you're a Madonna fan.

The good news is that most of the services offer free trials, since you won't really know what's stored in the music vault until after you join. If you don't like the service, be sure to cancel before the trial period is up or you'll be billed for at least a month.

There's nothing to prevent you from using a mix of services--downloading songs from MSN Music and subscribing to Napster for everyday listening. Since most services only require a month-to-month commitment, you can cancel at any time. To choose the right service, it helps to understand a bit about digital music files and copyrights.

You've probably heard about MP3 files, the digital format that launched the online music revolution in the 1990s. It shrinks the size of audio data while preserving sound quality, so music files can be easily distributed over the Internet. While MP3 remains very popular, two other file formats are hot on its heels.

AAC (Advanced Audio Coding) has improved on MP3 by requiring less data to reproduce the same sound quality. Songs downloaded from Apple's iTunes Music Store are encoded in this format.

WMA (Windows Media Audio) has the same audio quality as MP3 with only half the file size. This means that you can store twice as many songs on your hard drive or portable player than with MP3.

While there are other formats in use, AAC, MP3 and WMA are the big three formats used by digital music services. Your personal computer can probably play songs encoded in any of the formats, but most portable music players cannot. For instance, iPods play MP3 and AAC files, but not WMA files. Bottom line: Your portable player may determine which service you can use.

It took the music industry a long time to embrace the digital music revolution, because it feared losing control of its product. Since the industry makes its money by selling CDs, if people can freely exchange perfect digital copies of songs, well...there goes the profit. To allay this fear, engineers have built technical safeguards into some digital file formats that control duplication and sharing of music. Referred to as Digital Rights Management or DRM, both AAC and WMA files employ DRM technology (MP3 files don't).

This is important because it restricts what you can do with songs you download. For instance, you may be able to burn a song to a CD only a limited number of times.