All about MP3 and WMA files: A digital audio primer

Audio How-Tos

Question: I know MP3 files are music files, but can you tell me how they came to be, how to use them, and where to get them? – Ron

Answer: Here’s a primer on digital music files on your computer. MP3 files are digital audio files. They are most commonly used to store and play music back. But before we discuss further what these files are, how to get them and how to listen to them, perhaps it’s worth discussing why they came to be in the first place.

In the mid-1980s, the recording industry changed the process in which they recorded music. They started recording music in digital format, instead of using an analog method. Digital music is quite literally songs recorded into a data file. The file can be stored on a tape or any other thinkable medium. In music’s pure digital form, these files are very large, somewhere in the order of 10 megabytes of file size per minute of music.

As you might imagine, songs which run four to five minutes can be around 50 Mb in size. It made sense to use compact discs to distribute these files. The average compact disc can store 650 Mb of data or roughly 70 minutes of music which is ideal for albums. As digital music took hold, home computing also began to take off. By the early 1990s, computers were coming equipped with CD drives that were capable of playing audio CDs.

With the arrival of modems, it became possible to transfer files from one computer to another. Early modems were slow, though, so it was impractical to transfer huge audio files from one computer to another. For example, an average 50 Mb song would take over eight hours to move between computers using a 14.4 Kbps modem.

Soon, technology was developed to shrink large audio files into smaller files, so they could be more easily transferred. MP3 file technology was developed in Germany between 1987 and 1992 by the Fraunhofer Institute. It was quickly adopted through the mid-1990s and the era of MP3 music was born.

Today, an average five-minute song stored in MP3 format is only five or six megabytes in size. Such a file can be transferred using a 56Kbps modem in 12 to 15 minutes, rather than hours. This is possible because the data in the music file is compressed. In this process, the file is made smaller by removing some audio data. In addition, repetitive patterns of data in a file can be removed temporarily and replaced by a tiny marker. When the song is played, this marker is then pulled out and the original data pattern is put back in. The listener never notices any difference.

While MP3 is the most used compressed digital file format, you may also encounter WMA files, a digital audio format developed by Microsoft. Using these two file formats, music can be shrunk to a more manageable size without compromising a great amount of its sound quality. Wikipedia Audio File Formats

So now you know where digital music files came from and what they are. Now let’s move on to how and where you can get them.

First, you should know that you can create your own music files using your computer and special software, but let’s leave that for another time. Meanwhile, there are a variety of Web sites on the Internet where you can get MP3 and WMA files. Here’s a list:

  1. File-swapping services and peer-to-peer networks: These popular sites connect computers to each other so they can trade digital music files. You connect your computer to the service via the web as do thousands of other people. All the digital audio files on your computer are indexed and listed on the service. Other people on the service can select music tracks from your computer and download them from your computer onto theirs, usually for free. You, in turn, can download music from their computers the same way. (Beware: finding files this way may violate artists’ copyrights.) Sites that take this approach include: Morpheus and Bearshare.
  2. Free music sites: You can also legally obtain music in MP3 and WMA formats from some digital music sites. Some musicians offer some of their music for free download to promote themselves. Both unknowns and established artists do this. You can find these royalty-free files from such Web sites as MP3.com and yahoo.com, and lycos.com.
  3. Pay sites: There are also sites which offer music you can pay for. These sites collect royalties for the downloaded files and distribute them to the artists who created the music. These sites include Napster, Musicnet, and Rhapsody.

Once you’ve downloaded an MP3 or WMA file, the next step is to play them on your computer. Most PCs with versions of Windows 98 through Windows XP already have that capability with Windows Media Player. (Click your Start button, then go to Programs, then Accessories, then Entertainment, where you can click on Windows Media Player).

Updates for Windows Media Player can be found on Microsoft Windows Media.

If you’re interested in software that might offer more advanced features, you might want to look at programs such as:

  1. Winamp – Check out the book and CD MP3 Power with Winamp.
  2. Ultraplayer
  3. Sonique
  4. Musicmatch Jukebox