there was a software that breaks down each instrument in a song for you on different lines regardless of the song as long as they are not playing the same note and you can change the note of any part of it, in theory make a completely new song with them. I imagine you can delete instruments also. I cant remember the name but Im going to try and find it.
damn I really wish I remembered the name of it. It came out maybe 4 or 5 years ago and was amazing. I even made I thread on it back then but I cant remember what I called it. shit. I hope someone remembers this