I will create stems from stereo audio files or any music

It's simple as that. 
You give songs, any song, and I give you back the at least 3 separated audio files contending the instruments audio of that song. 
If you give me and audio file, I will also separate it in 3 audio files.

The audio files will be delivery in wav following the quality of the track you send me. 
If you want I can search for a better quality tune if yours is in mp3 file or bellow 320kpbs of quality.