All three sang a verse. I don't they did that on the record.
Also, this version is a little pepper.
I did notice that only one guitar is plugged in, but the vocals sure seemed live.
and, we hear strings nobody us playing.
I wonder if they record earlier in the day and they mimed to the canned music but actually sang it live.

...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.