Too many of the "folk" tunes I have heard from movie soundtracks sound contrived or over-arranged, or both. It's a delight when one comes through relatively unscathed. Jagger doing the "Wild Colonia Boy" was a fair example. Who remembers the old Glenn Ford epic, "Advance to the Rear?" It was a western (spoof?) in which some Randy Sparks material appeared. The one most people remember is "Today." Though it is not a folk song, it got a lot of air play.
There is a 1940's western in which Forrest Tucker appears as a good/bad guy. The picture wasn't particularly memorable, but his singing of "Skip to My Lou" was a surprise. The guy had a fair voice.