[Baloo]

Do you mean it's a minefield* :P

Not sure it's as much of a problem as you're making it seem though.. likely there can be enough iteration that it would not be distinguishable.

Also lots of mainstream artists ignore copyright anyway (Kanye West etc). Plus you could just use training data that is from public domain stuff if it was really such an issue, there is decades worth of music that are outside of copyright law.