Not so Elmore: the Batties are constantly producing new material, not just doing covers of older songs and tunes.
As for covering songs: there's this saying about "making a song your own": that doesn't necessarily mean radically changing it. but it does mean not slavishly following every little nuance and riff done by the original artist - or in the case of a traditional song of no known composer - following the so-called definitive archive version.
Quoting from Jeri above: agree with that entirely!
"What gets in the way of me enjoying a song is the feeling that the performer is just trying too hard. It can be deliberately trying to sound like the original, or deliberately trying to sound different from it by changing things. It's the "deliberate" part that gets to me. I think if someone sings another's song, they can't help sounding like themselves."