You may or may not know that making a mix tape of songs from your personal music collection to give to a friend as a gift... is illegal. Yep, that's right. According to the law, when you purchase a CD (or LP or tape), you are free to do whatever you would like with it, as long as you only make copies for personal use, and never broadcast the contents of the CD, and don't ever charge folks to listen to it... unless you get the permission of whoever owns the copyrights to the music. Whew. That seems pretty restrictive. It is, and for good reason. These rules protect the artist and copyright holders and ensure that they are paid for their work.

The same rules apply in cyberspace. You can rip every CD and LP and tape in your collection onto your computer for personal use (to make custom albums, or to listen while working, or to transfer to a portable player device). You should not trade MP3s that were made from copyrighted material with friends and you should not create MP3s from CDs that you do not own. And you should not broadcast copyrighted material over the Internet without the authorization of the copyright holders.

Currently, you are held to these rules only by appeals about the welfare of artists and threats of legal action. In the future, however, there will be measures in place to prevent illegal use of copyrighted material. The Secure Digital Music Initiative (or SDMI) is a collection of representatives from the recording industry and technology companies, whose stated goal is to develop a standard for protecting the legal rights of copyright holders. This will most likely involve including security measures in recorded music that is sold, digital audio software, and digital audio hardware players. Several digital audio formats already support security measures: Windows Media (WMA), MJuice, and Liquid Audio formats provide varying levels of security built into the actual song files.

Sounds pretty gloomy, right? Well, actually, there will be at least one upside. With security measures in place, major record labels will be much more open to the sale of their catalogues on the Internet. Imagine, your favorite hot new single, an out-of-print jazz album, a rare B-side, all available for purchase and download. This might very well revolutionize the way that we buy music. I, for one, will still probably schlep down to my local record store for most of my purchases, but I certainly won’t hesitate to buy and download tracks that I can’t find or that are not available in hard copy.

That’s pretty much it for our overview of digital audio. The next section is a glossary of terms that we have used here and others that you might hear or see in reference to digital audio.

Happy listening.