Only one person mentioned Odetta!

It was Odetta's recording, live in performance,
that introduced me to this song.

Her version is extremely spare. Just her and her six-string guitar.
In between verses she just alternates two chords on the guitar,
using some of that rhythmic touch she learned from Libba Cotten.

In terms of chords in a minor key,
the chords would be iv - i - iv - i.
Odetta, as well, sings,
"He bowed his head in the moonlight."

I believe this album is Odetta Live at Town Hall.