Outsider or Unplugged

Bobby came by today. I invited him in for a cup of tea, "...but leave the guitar outside on the deck. It'll be just fine."
He came in and looked at the latest car paintings.
I said, "What do you think Bob? Are they outsider art?"
"No," he said, "I think they're like more like, you know, acoustic or something."
"Acoustic? But that's an auditory term, this is visual art. Do you mean aesthetic?"
"No, acoustic. You know, like in 'unplugged'..."