If 'legally' filling up your MP3 player with gigabytes of music for less than the retail price of a single album interests you, then it is time to choose a music subscription service. Digital music is an emerging market with three major players enticing thousands of people to give up pirating their music and actually paying for it.

When taken into consideration that people have been stealing music long before the advent of the MP3 file, which made pirating music a widespread epidemic, why now are people all of a sudden going straight? So many, that 2005 was the first year legal downloads of music exceeded illegal downloads on P2P sites. Thank Rhapsody, Napster, and Yahoo Music Unlimited for finally offering a model that makes sense. Instead of buying songs or albums, they offer subscribers the ability to rent their entire collection of over 1 million tracks for a low monthly fee. Buying thousands of tracks on Apple's iTunes would cost thousands of dollars, where you can easily download 10,000 or more songs to your MP3 player through a music subscription service for as low as $4.99 a month. Aside from the cost savings, renting music has more advantages over buying. For one, it is convenient. Imaging having over 1 million full length high quality songs at your fingertips, so whether you want to listen to your favorite song, something different on an impulse, or are just curious about an emerging artist, you can have it all. On top of that, you don't have to worry about slow downloads, poor audio quality, corrupt or infected files.

Convinced? So which music subscription service is right for you?

While they are all pretty comparable, Rhapsody is probably the cream of the crop. They offer the most streamlined interface and the best jukebox functionality, all accessible from any PC connected to the web. Artist bios, radio stations (which allow you to skip songs), and advanced playlist features are all integrated into the interface. For $14.99 a month, this is a great value. Subscribers also have the option to download songs for 89 cents a track.

Napster also has an attractive interface with advanced playlist features and a massive catalog of music that is continually growing. It has a few nice personalization features, but transferring songs to an MP3 player can be more difficult with Napster than the alternatives. For $14.95 a month and 99 cent tracks, it is still a great value.

Yahoo Music Unlimited is the least expensive option, charging only $4.99 a month and just 79 cent tracks. It includes a nice jukebox, radio stations (which allow you to skip songs), and can integrate with the popular Yahoo Messenger client. If the appealing price outweighs a lack of extras like artist bios and a few bugs here and there, then Yahoo is probably the way to go.

With digital music sales soaring, it is a safe bet that all three of these music subscription services will flourish and continue to develop even more features, grow their already extensive catalogs, and convert more and more pirates into renters.