While lots of the sound comes from the recording, many of the fans sang along. But nobody was really that into it. Keep in mind it was a Wizards game so the excitement level before they show Redskins logos is pretty much that of a library's. It was about as loud as an arena half filled with Nets fans could get.
Later in the game there were several weak attempts at RG3 chants that never went too far. Check out the video: