Bill Amatneek is a fine musician and the original bass player with The David Grisman Quintet.

As for the tune, if it is modern and anyone can recognise it, you probably need permission.

Some people claim that Wood Guthrie never wrote a melody in his life, but everyone recognises "This Land Is Your Land" as his. "Wildwood Flower" and "Great Speckled Bird" both have many melodic clones.

A parody, as far as I know, frees you from needing permission.