Most of the activity is done without the blessing of the music industry, which seems clueless as to how to proceed. If you go to a Web search engine and type in MP3 as your search criterion, you'll be inundated with various sites extolling the virtues of this scheme. You'll also find the players and lots of music. WinAMP, MAplayer, and others. I use MAplayer because it can turn an MP3 file into a .WAV file.
Aficionados believe that WinAMP is the best out there.
MP3 songs are compressed digital files that play as .WAV files. Proponents claim no degradation in sound quality from uncompressed CD audio. The rule of thumb for MP3 is 1 minute of CD music per megabyte. A CD containing MP3 audio can contain 14 hours of music. A quad-density DVD might contain as much as 400 hours.