Irish set dance Church in the form of the Public Dance Halls Act 1935. The rise of rock and roll in the 1950s caused the popularity of set dancing to fade. However, in the 1980s a revival started and many sets that have not been done for forty years or more are being recovered and danced again. To start, four couples are arranged in the form of a square to dance with each couple being in the middle of the sides of the square. Both the eight dancers in the group and the dance itself are called a "set". The dance is a
Challenge square dance partially filled by real dancers. Challenge dancers must learn to do their part of a call in a particular formation even though many of the other dancers – possibly all of them – are missing. This requires both a clear understanding of the call definition and the ability to remember where the positions of the formation are without the usual visual and tactile cues. Calls which cause the dancers to change from one formation to another ("shape-changers") are especially challenging to dance with phantoms because the positions themselves will be changing and the entire formation may have to move to