Back in October, after performing to a packed house as part of Pittsburgh Plays Petty, guitarist Byron Nash was approached by a woman and her mother. Through tears, the woman explained that her father, who had recently died, was a musician and a Tom Petty fan, who especially loved the song “American Girl.”

“Something about the way we had played that song touched them,” Nash recalls. He felt almost uncomfortable accepting the woman’s praise – “Like, well, it’s not my song” – but he realized “That’s how [music] transcends. It doesn’t matter if it’s your song or someone else’s song,” he says. “I gave it a lot of integrity and I cared about it and that was someone I reached.”

Tribute shows like Pittsburgh Plays Petty occupy a strange and sometimes divisive space in the world of live music. Nash’s experience represents the best sort of outcome. But done poorly, or for the wrong reasons, audiences — subjected to self-indulgent or questionably-conceived renditions – will wish that they’d stayed home with their record collections. And, of course, there are the sneers that come from a certain kind of purist for whom original music is the gold standard.