I seem to remember the entire crowd of over 50,000 helping them with that. Their GE was through the roof. WITHOUT narration.
Also, narration can be good if used properly. Example: I believe that the fight announcer in the Bluecoats' show "Knockout" greatly contributed to the overall effect of the show. Quick, subtle, and it just put the icing on the cake. It wasn't the platter, batter, icing, sprinkles, and the birthday candles like the Cadets.