Not entirely,for music in the US there is compulsory licensing in the law. The orignal copyright owner does not need to agree as long as the covering musician

Not entirely,for music in the US there is compulsory licensing in the law. The orignal copyright owner does not need to agree as long as the covering musician complies with the terms of the compulsory license laws. http://en.wikipedia.org/wiki/Compulsory_license http://en.wikipedia.org/wiki/Compulsory_license