Music Appreciation

...have no cord running to them. The guy on the right has a cord coming out of his guitar, but the amp is off. (Both toggle switches are down; no power)
It's definitely not the studio version, though.
With singing, I can always tell if it's live. In the days before synching video to audio, I'll see someone quit the word but I stoll hear it: or the opposite; or a singer pull way off the mic and no change in volume.
I see none of that here. I'm convinced they're singing live.
The music is an odd situation.