It can be a muddy area but if you yourself know you are altering, modifying, or editing an existing
piece of copyrighted music and then calling it yours, the only way you can feel safe from legal action
is by not making it public. Verve had even purchased the rights to use a sample for their biggest hit
Bittersweet Symphony. It was a great song but they wound up getting sued and lost all the money
they made on the song I think because they used more of the sample than they had paid for. It's
better to write your own music. Otherwise what's the point?