BOSTON — what is mp3? it stands for MPEG-1 Layer 3 and was created in 1992, says Eric Scheirer, a research assistant at the Massachusetts Institute of Technology's Media Lab. It's a layered audio-compression format that has a small file size, offers near CD-quality sound, and transmits music easily over the Web. MP3 is an open standard - no one controls it. Technically, MP3 makes music more efficient because it trims excess data and only compresses the part you can hear, Mr. Scheirer says.
MP3 is legal, but it makes it easier to copy and transmit copyrighted songs without permission because not many MP3 tracks have watermarks or playback restrictions. Musicians and Web sites sell or give away songs legitimately, but most MP3 sites are illegal.
How does it work? To play an MP3 track, you need a player and, for better sound, a pair of speakers connected to your computer. You can download dozens of different players from mp3.com, such as Winamp, the most popular for PCs. On the same site or on others such as goodnoise.com, you click and legally download songs for free or for about $1 each. It typically takes three-to-five times the length of the song to download it, Scheirer says. High-speed T-1 lines reduce download time to a few seconds. Then you drag the file onto your virtual player deck and click the play button. You can also take songs with you by transferring them to a portable player, like the Diamond Rio, which stores about 40 minutes of music.