Hi John, I don’t know all the legal stuff. But here’s what I believe. Earl certainly had ownership of his music, the person who created the TAB may or may not have a stake in ownership. The publisher would also have some kind of stake in it. Earl’s wife was his manager and she would have had some kind of contract drawn up to protect Earls assets. Each of these stock holders would be entitled to some form of royalties income.
Sometimes artists do sell their copyrights and the owner of the copyright is entitled to recover income from the sale and public performance of the works so long as the copyright remains valid.
Not so long ago Warner/Chappell Music owner of the copyright to the song Happy Birthday tried to recover royalties from schools etc but a US Judge ruled the copyright invalid.
Check this out