hb, all Kirk's lessons on here are not copyrighted. They are in the public domain. Apart form his originals of course. So Amazing Grace is in the public domain.
If you want to search for music that is public domain, this is a good place -
List of Public Domain Music and Songs
Cheers
Clancy
"Even if you're on the right track, you'll get run over if you just sit there.". Will Rogers