The history of Irish dance started when the Celts arrived in Ireland from central Europe over two thousand years ago. Bringing with them their individual styles of dances and music. 

The Footwear

Most women in Ireland, until over a century ago, would have danced barefoot; which gave them a natural grace and lightness which today’s dancers strive to maintain. Girls began wearing softshoes, known as ghillies, in 1924 while dancing jigs, reels, and slip jigs. Men worked on the land, and therefor wore hand-made rawhide shoes which were light and suitable for dancing. Fishermen on the coasts of Ireland wore wooden soled shoes, and when teaching traditional music was outlawed, the rhythms of the various dance tunes were maintained by tapping the hard shoes on the flag stones and tiles.
Today’s modern Irish dancers wear specially made ‘hard shoes’ and soft shoes. After black stockings were forbidden by the Church for being seductive, female dancers switched to white socks- poodle socks- which are still worn today, especially in competition where they contrast the black shoes. Tights are however slowly gaining popularity due to theatrical presentations. 

The Bodhrán

The Bodhran is framed drum, usually of bent wood and goatskin tacked to one side, the other side is open ended for one hand to be placed inside the drum to control the Pitch and timbre.
The very origins of this instrument are shrouded in history. One legend dates its use to 1603 where it was used as a battle drum for the Celtic forces of “Tyrones Rebellion” fighting the forces of Queen Elizabeth 1.
Recent years have seen a significant resurgence in the Bodhrans popularity in no small part due to the work of Irish Composer “Sean O Riada”, who declared the bodhran to be the native drum of the celts with a musical history pre-dating Christianity.  
From mysterious origins the Bodhran has become popular throughout the world, known as the Irish instrument central to the driving rhythms, on which Rhythm of the Dance is based. 

Fiddle

The lovely, lilting sound of the Irish fiddle is synonymous with Irish music. The term fiddle may refer to any bowed string musical instrument most often the violin While fiddle playing, or fiddling, refers to the style of music playing which is generally louder and more rhythmic than traditional classical violin. Fiddles are generally strung in a different way to a classical violin, in order to capture a uniquely Celtic sound.
The fiddle emerged in 10th-century Europe, deriving from the Byzantine lira By the 11th or 12th century the bow had been introduced to Ireland and, upon arrival in the Emerald Isle there was a rapid evolution, as the lyres were adapted for bowing.  As early as these middle ages Ireland was fast gathering an international reputation for the quality of its musicians.
For centuries, Irish fiddles have been a powerful part of the cultural tradition of Ireland and are of the most important instruments in the traditional repertoire.
By the early 19th century, certain modifications and improvements to the fiddle were in place…chin rests for comfort appeared around 1820, and the range of the instrument was increased by the creation of a longer fingerboard. In the early 20th century, Irish families and friends would gather in the country, often at crossroads, and practice Irish fiddling in a group. Get-togethers at houses and pubs were also very common the instrument became a way of uniting the Irish people through traditional folk music. Modern musicians remain intrigued by the traditional folk melodies and techniques of the past and contemporary Irish musicians use the fiddle to add traditional elements to a variety of styles, including pop and rock. The fiddle is considered the oldest traditional Irish instrument of all. Irish fiddle playing today has never been more vigorous, whether at a professional or amateur level, with an extremely high standard of playing and a strong demand for the music both in Ireland and elsewhere.

The Costumes

There are no specific rules governing the design of  costumes in step dancing. Traditional costumees are based on the simple princess cut dress. The dresses are decorated with Celtic designs, reproduced from those seen in The Book of Kells, The designs are created with applique and emboidery, and Colors have always been present to highlight the designs;  The skirts are gored, box pleated, split panel, or knife-edged- all to allow free leg movement. Skirt length is to be above the knee by no more than four inches as regulated by the irish step associations

Uilleann Pipes

The Uillean Pipes (pronounced ill-in) are uniquely Irish. The uilleann pipes had their beginnings in the early eighteenth century. Pre-dating the Uillean pipes the common form of Irish pipes “the Irish war pipes” were very simular to the present day Scottish pipes. At one time bagpipes were popular throughout Western Europe and parts of Asia. Borrowing and combining ideas from other countries like Scotland, England, and France, the Irish began redesigning their bagpipes.
 The resulting uilleann pipes are regarded as outstanding among the pipes of the world for their mellowness and sweetness of tone. These newer pipes had a chanter of two full octaves compared to the old war pipes with just nine notes. Instead of a blowpipe the bag was inflated with a bellows operated between the waist and the elbow. The final design came about the late eighteenth century with the addition of the third drone. These pipes are played in a sitting position rather than standing or marching like with war pipes or the Scottish Bag Pipes. 
The Gaelic word for elbow is uilleann hence the name Uilleann pipes.

Irish Flute & 
Low Whistle

The wooden instrument known today as the Irish flute was actually not developed for that kind of music. It had been used in orchestras until it was replaced by the modern metal flute, 
When the modern orchestral flute was developed by Theobald Boehm in the mid-19th century, simpler six-hole wooden flutes began appearing in pawn shops. These were sold cheap to traditional musicians who used them to play traditional Irish music. Soon a few instrument makers began duplicating the earlier wooden flutes for folk players. The newly crafted Irish flutes still had six finger holes, but now only a few or no keys as there are few sharps or flats in traditional folk music. Irish flutes are also traditionally used in bands made up of only flutes and drums. Flutes of three to seven different sizes (and ranges) are used together. The center of this band activity is Northern Ireland.
Today, Irish flutes are made from woods such as grenadilla, boxwood, or bamboo, or polymer. They can cost anywhere from a couple of hundred dollars / euro to several thousand.

While its earliest origins are lost, the Irish harp has a certain history dating back at least 1000 years. Brian Boru, the last High King of Ireland (d 1014), is said to have been an accomplished player.
At this time, the Gaelic harp was revered in Celtic culture (and all over Europe). It was commonplace for  Irish kings and chieftains to have their own resident harper.
When The English monarch Henry VIII declared himself King of Ireland in 1531. Such was the fame and prestige of the Irish Harp, it was chosen as the official national symbol of Ireland and used on the coinage of the time. 

As the Celtic social order waned, the Gaelic harp became an emblem of resistence to the Crown and England. As such, it was banned at the end of the medieval period and the old Celtic harp tradition began to die out. By the 19th century, the Irish harp, was practically extinct. 
In 1792 a group of traditional harpers assebled in belfast for a traditional harp festival where the musician and folk music collector, Edward Bunting wrote down the music they played and the terminology of the harpers. Amazingly this appears to be the first time traditional Gaelic harp music had been recorded on paper, thus saving these tunes for our enjoyment. 
The traditional Irish harp’s distinguishing features are its use of wire (usually brass) strings and its resonating chamber carved from a single log (traditionally willow). The highly tensioned strings are played with fingernails, producing a very clear sound.