How it was,

While in Montreal on the Animals tour, a fan kept screaming and letting off fireworks during the acoustic "Pigs On The Wing Part II." The fan, obviously distracting the band, was making Roger increasingly irritable. When the fan started climbing up the fishnet that separates the band from the crowd Roger spat in his face. Later that night at the hotel he felt bad for what he done. He realized in order to perform he had to isolate himself from the crowd. What he envisioned himself behind was a wall. The rest is history.