It's up to you. All over the UK and also in France. We try to find sites in attractive locations, where there are also places to visit and things to do. There will be a field to camp on and a hall or marquee for eating, dancing, playing, singing and any number of other activities. The whole idea of these holidays is to make our own entertainment, with the leader drawing on the interests and talents of the people on the week.
Nobody has to join in with anything.
The chances are there will be quite a few musicians around ranging from the first-time comb and paper enthusiast to the very competent squeeze box player with the occasional professional thrown in for good measure. Quite a few people will help play tunes for dancing in the evening and many more will be keen to learn some new tunes at the morning sessions. Dancing ranges from the simple to the slightly difficult, and if you've got two left feet it could add to the fun. Many of the activities on these weeks happen because somebody had a good idea at the time. 100 people on a river boat trip, a mass invasion of the nearest beach, an adventure walk for the under tens, an England versus France football match, yoga, madrigals, jazz, limbo dancing, a picnic, a trip to the pub - all these have happened not because the leader said so, but because somebody wanted to organise it.