A few years ago I got a request to make a fiddle tab chart for Great Speckled Bird. The request came from an online student who wanted to play this at a fiddle contest.
I must have wanted to chart this tune anyway. My result was a simple version of the tune, much like it was sung by Roy Acuff, followed by a fancier fiddle version.

And the pdf of Great Speckled Bird.
Here is another Gospel song, often sung at folk gatherings, Amazing Grace.