In America, square dancing has been the most popular form of folk dancing since the early days. In early times, when men and women worked in groups to build a barn   or harvest crops, they danced when the work was done. The music came from the violin for the most part, but if there was no one to play a musical instrument, clapping was used to produce the rhythm to which people dance. The early settlers danced in a store, in a barn, or in a farm kitchen. A square is formed by four couples  who stand facing the centre of the square. Each couple stand on one side of the square, the boy on the left and the girl on the right. The caller is an important part of the dance, since he tells the dancers which steps to do. If the dancers do not know the steps, he teaches them. It takes time to learn to be a good caller, and good callers are always in demand . These are the names of some of the steps the dancers do: Form a square; Circle; Honour your partner; Swing your partner; Form a star. There are many more. As the callers tell the dancers what to do next, they move to form the pattern he calls. Large or small numbers of people can dance at one time. Sometimes 800 or 1,000 people may be dancing at the same time. Or there may be only one square of eight people. Special clothes are worn by some when dancing. This makes the dance more colourful to watch. The special clothes are different from place to place. Women often wear full skirts of various colours with a pretty blouse. Men have coloured shirts and western trousers that they wear only when square dancing. In some country areas, everyone wears his best clothes. Today in some parts of the United States you will find some schools, clubs, or groups square dancing for fun. From the passage we know that square dancing came from  _  .
the clubs the schools big cities the countryside