I tried to do a little research about this one, but it was kinda difficult to digest. Here is what I gathered, in a nutshell: WMA is a common format that works on many audio players including VLC player, Windows Media Player, RealPlayer, and Winamp. Old stereo systems may not read this format because they are designed to handle CDA format (format for music CD's)...but certain players and stereo systems are now catching up in terms of the file formats that they can handle.