There are a number of traditional Irish dances, most famously the Irish Step Dancing popularized by Michael Flatley in Riverdance. However, social dances such as céilí and set dancing are more common in daily life. Obviously, many dances from around the world are performed in Ireland, and are taken up and often modified. Here are some of the more common and more traditional dances:
Céilí: (Pronounced 'kay-lee') These dances are group dances following a set formula, somewhat like a line dance. They appear to be based on dances that have been around since the 1500s, such as the Rince Fada and the Rince Mór. These, along with other aspects of traditional Celtic culture, were suppressed by the English during the Penal Laws, from about 1607 to 1897. They once again became popular as part of the Irish Culture movement of the early 1900s.
There are a number of standard dances, in the form of round dances or group dances in which the dancers face each other in long lines. In many ways they resemble a barn dance or contra dance, but these dances do not have a traditional caller -- if they do have a caller, they are just there to remind dancers of the formalized steps, not to choreograph the dance. Individual pairs may embellish on these steps as they see fit. Céilí dances also share a number of stylistic features with step dances, including dancing on the balls of the feet, an emphasis on vertical movement, and dancers moving to the sides while continuing to face forwards.
Set dances: These are based on the quadrille, which was the fashion in France during the early 1800s. The set dances spread throughout England and Ireland, taking on local flavors. Many sets are referred to by the place where they gained popularity, such as the South Galway Set and Clare Lancers Set. They incorporate Irish traditional music, tempos, and dance steps, making the Irish set dances distinct from those of other areas.
Set dances are danced by four couples arranged in a square, performing a series of formalized formations. In competitive or show dancing the four pairs are likely to dance continuously as they go through comparatively complex figures, but in larger social dances the group alternates between figures in which everyone dances and figures in which one or two pairs from each set dance.
Set dances decreased in popularity during the reemergence of céilí dancing, and again as more modern dances and clubs continue to take the attention of the modern youth. Today these dances have approximately the same role as ballroom dance does in America, although they saw a resurgence in the 1980s.
Step Dances: Irish step dances are primarily done in formal settings such as competitions and public performances, and are not generally performed as social dances.
It is unclear how old the tradition of step dancing might be. Sean-nós dancing, also known as old-style stepdancing, is viewed as being very old in origin, and may have been popularized by travelling dance masters showing off their skills in hopes of drumming up business, or may have been simply a way for a talented dancer to show off their skills. These older step dances tended to favor a hard shoe on a hard surface such as a stage, a door, or even barrel top, making the percussive noise of the dance steps were an important part of the performance. The extremely limited use of floorspace was a matter of some pride. Dances covered varieties of the reel, slip jig, hornpipe, and jig. Local dance masters and other talented dancers might compete, or just show off, at local fairs, sporting events, or gatherings at the pub.
The first recorded formal competition was in 1897, and since that time the An Coimisiún le Rincí Gaelacha (the Irish Dancing Commission), has formalized competition rules and identified about 30 different standard 'sets' of step dance. Modern step dancing emphasizes a rigid torso and little or no arm movement, with the arms held stiffly at the sides. This has been modified in many popular performances (such as Riverdance) to include plenty of arm movement, while maintaining the limited movement and strict posture as a base from which these flourishes arise and to which the dance returns frequently. In either case, rapid, precise foot work with lots of vertical movement and high steps are standard.
Dancers may choose either hard shoes, much akin to tap shoes, which are specifically designed for noise production with fiberglass 'taps' on the toe and heel, or lighter, soft shoes. The soft shoes come in separate designs for boys and girls, with female dancers wearing laced-up slipper-like shoes called ghillies, and male dancers wearing black leather shoes called reel shoes, akin to jazz shoes but with a hard heel.
Despite a long tradition of formalizing the base forms of popular dances, all of these dances appear in innumerable variations, each of which are modified by individuals schools and dancers. Forms of these dances have also spread to other countries, both through immigration and imitation, and dance traditions such as buck dancing, flatfooting, clogging, and tap dancing owe some of their heritage to Irish dancing.