Irish set dance, sometimes called "country sets", is a popular form of folk dancing in Ireland. Set dances are based on quadrilles, which were court dances. These were transformed by the Irish into a unique folk dance of the Irish rural communities. Promotion of Céilí dance during the 1930s and 1940s (abetted by the Public Dance Halls Act of 1935), and 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 sequence of several dance figures, which usually have a common theme or structure. The figures usually begin and end with repeated parts that everyone dances, and then during the figure each couple or pair of couples will dance separately. In the set, the couple with their backs to the band are traditionally named "First Tops" with "Second Tops" facing them. The couple on First Tops left hand side is called "First Sides" with "Second Sides" facing. Usually the First Tops are the first to dance, with some sets having First Sides and then Second Tops going next and some having Second Tops and then the First Sides. Second Sides is almost always the last couple to dance, and is therefore a good place for beginners to start, as they get more time to watch the demonstrations of the figure that the other couples give.
Set dances from a particular region usually have similar elements. For instance, sets from the Connemara region (such as the Connemara Reel Set, the South Galway Reel Set and the Claddagh Set) have the First Sides on the right of the First Tops, and sets from the Clare region often involve footwork similar to Irish competitive Stepdance or traditional freeform Sean-nós dance (which emphasizes a "battering" step).