Stagecoach starts from age 4, not 3.
The 4-6 year old class is called Early Stages and it is only 90 minutes, not the full 3 hours. They do half an hour each of drama, singing and dance.
Even in main school when they stay for the full 3 hours they are always in classes with children of a similar age. No class is larger than 15 and the ages in main school are something like 6/7 - 9/10 year olds, 9/10 - 12/13 year olds and 12/13 - 16 year olds.
Dance in Early Stages is learning to stand properly, move in time, skip, maybe putting a few simple steps together to create a dance.
Even in main school when they stay for the full 3 hours they are always in classes with children of a similar age. No class is larger than 15 and the ages in main school are something like 6/7 - 9/10 year olds, 9/10 - 12/13 year olds and 12/13 - 16 year olds.
Drama is very teacher led. Improvisation, drama/confidence games, going on a journey (think bear hunt) that sort of thing.
Singing is simple warm ups and learning simple children's songs.
Parents have to leave as they distract the children. The child is more concerned about what mum thinks than what they are doing. They get on much better and under less pressure without them.