CoffeeCup Web JukeBox will only play MP3 files. It cannot play WMA, WAV, AAC or any other type of audio file. However, if you have an audio converter, like the one found in CoffeeCup MP3 Rip & Burn, you will be able to convert your other audio files to MP3 and use them with Web JukeBox.
If your audio files are protected with some type of DRM protection, you will not be able to convert them with MP3 Rip & Burn. Also, files downloaded from iTunes, Napster, Wal-Mart or any other music service may have some type of copy or DRM protection and may not work with Web JukeBox.
As an alternative to the pay-for-play services above, you can look at free music locations like CNET. Sites like these tend to have less mainstream music.