Traditional Song or Cover?

Listening to Radio National I stumbled across a beautiful version

of "Won't You Come and Sing for Me" being performed by

Chris Theli (mandolin guru from Nickel Creek https://www.facebook.com/NickelCreek).

His stripped back version of this traditional gospel song inspired me to get a bit Indie Bluegrass in this version of Wayfaring Stranger.

I have been busy writing my own songs lately so messing around with an existing tune made me wonder ....When does a cover stop being a cover and become a traditional folk/gospel standard?

Whatcha all reckon? https://www.facebook.com/alfalfamales/