Elvis Presley... he couldn't stop laughing while the choir was singing... (26th August of 1969 at the International Hotel, Las Vegas). Even if the 'moment' is very known hear it from time to time is a really laughter therapy!...
Pay attention at 00:47... he says "Do you gaze at your bald head and wish you had hair?", it seems he saw someone at the audience with a funny toupee... but not much hair! The choir didn't help too much with its endless huhuhuhu...