If you watch a movie, listen to a piece of music, or read a book you are creating an (albeit imperfect) copy of that work in your mind. Does that make you the property of the publisher? I would hope not.
Similarly, copyright and patent law was intended to give a temporary monopoly to creators so that they can recover the cost of developing the work. It probably was not intended to enforce this notion of intellectual property, which seems to be a twentieth century creation.
So, returning to the original question: is it wrong to copy 'free' music? I would argue that the copyright holder is surrendering their temporary monopoly by giving it away, which is to say that they are not attempting to recover the costs of developing and recording the music. All of this talk about licensing is nonsense too: when you buy a book, a recording, or a video, you are not entering into a contract. A contract is a legal agreement, and there are certain things which it must fulfill. For example: there must be an exchange (what this site calls "consideration":
http://law.freeadvice.com/general_practice/contract_law/binding_contract.htm). Many license agreements don't guarantee anything beyond an empty box. So most licenses are probably invalid and the publisher/artist is circumventing the purpose of the monopoly: so what is wrong with copying a free work? I have a hard time coming up with a reason.
