I remember once in an assembly they had arranged a group of sisters and brothers to stand in the platform to sing every song in that day just to show us how it was done. It was supposedly because the CO wanted to make sure we were singing "loud" praises to Jehovah. It was one of the dumbest thing I've ever heard and took part in.
When the song would start all you could hear was the ones singing from the platform since they were singing through the microphones. Almost everyone in the audience was looking at each other with a smirk in their faces, while they tried to immitate the ones that were supposedly showing us how to sing.