"Lovesick Blues" was lifted from Emmett Miller of South Georgia. It was sung at the Opry while Miller was indigent in Georgia.

The music business is full of plagiarism, lifting or nicking songs, changing a note or two here and there such as with "Delta Dawn" which is the tune for the spiritual "Come and Go With Me To That Land".

The tunes that defy copying are generally those of the past well-known "show" writers such as Kern, Berlin, Gershwin, Porter et. al. Even the lyrics of those have been nicked by pop lyricists of today.

One of the things that makes a pop song successful is its familiarity which can be said for
folk songs as well.

Almost all of the Nashville country songs are derived from earlier sources.