In Modern Western Square Dance lessons you will be learning calls.  When you hear a call you and the other 7 people in your square do what you are supposed to do in that position.  As you learn more, the choreography can get more complex and if you were to look down from above, it would look somewhat like a kaleidoscope.  After 8 weeks when lessons are over, I expect to be dancing with approximately 40 calls and people can join a group of more experienced dancers on Wednesday night who are dancing with approximately 50 calls.  Ultimately we may end up with 60 to 70 calls, or not, depending on what people want.  I am a member of CallerLab, which is the International Association of Square Dance Callers and have twice graduated from CallerLab schools.