Derivative works need permission from the original publisher, while cover songs only needs a mechanical license. Or I'm I mistaken in assuming he only had a mec

Derivative works need permission from the original publisher, while cover songs only needs a mechanical license. Or I'm I mistaken in assuming he only had a mechanical license? http://www.harryfox.com/public/Licensing-GeneralFAQ.jsp#131 http://www.harryfox.com/public/Licensing-GeneralFAQ.jsp#131