What Do We Need to Cover a Song?

Dear Rich: Do we need permission by the original author/creator of a song to sell/distribute a song cover, or is it simply enough to credit the original creators on the release? What are the basics of licensing/clearing a cover song? Speaking of covers, we recently stumbled on Willie Nelson's version of The Warmth of the Sun. We wondered if this video was around when Willie was having his tax problems, because if it was, we don't see why the judge didn't dismiss all charges and grant Willie sovereign immunity. P.S. The song has a different meaning when you learn it was written the night that JFK died.
Right, you had a question. Check out our response to a similar question last September. And if you're still having trouble sleeping, check out all our other responses dealing with covers and compulsory licensing. (Type "compulsory license" or "cover song" into the "Search Dear Rich" box on the right.) Also, our book, Getting Permission, explains the procedures in detail.