I agree with Leadfingers.                                  Unfortunately the word "cover" in music has changed since its first use in the 1950s. Then a "cover record" was a straight copy of another popular record, usually (but not always) an inferior white artist recording a song by a superior black artist and robbing the latter of possible record sales. Thus the word had a derogatory inference. Nowadays the term is used about any artist singing a song originally recorded by someone else. And in a world of singer-songwriters, it is a put-down in a different way, inferring that the singer or band cannot be bothered to write original material.
This is nonsense   - as Richard Bridge explains. Apart from folk performers, the world of jazz singers is full of people who don't write songs. Billie Holiday only wrote a handful, but mainly sang wonderful personal versions of other people's songs. In rock'n'roll and country music the great Jerry Lee Lewis took songs from all over the place and stamped them with his own personality. And back to folk, the great Ramblin' Jack Elliott also only wrote a handful of songs, but my God, could he interpret other people's material.
And the list goes on........
I still like to use the word only in its 1950s sense. The folk tradition, by its very nature, encourages tha psssing on of material in a personal way - and long may it do so.