Music for Irish Step Dance generally falls into two categories, jigs and reels.
Jigs are danced in six-eight time, which means there are six eighth notes for each bar of the music. That gives the dance a sort of swinging feel. One, two, three, four, five, six. Two, two, three, four, five, six. Three, two, three, four, five, six. And so on.
The reel, on the other hand, stands in four-four time which means there are four quarter notes for each measure of the music. That gives the reel a more driving feel. One, two, three, four. Two, two, three, four. Three, two, three, four. Four, two, three, four. And so on.
Common instruments for Irish Dance include fiddle, accordion, flute, tin whistle and bodhran, or goat skinned drum.
While the jig and the reel are the most typical forms of Irish Dance music other variations include dances such as the hornpipe, typically an English folk dance that made its way into Irish Dance lexicons.
The slip jib is another variant. Slip jigs are unusual in that they are danced in nine-eight time. Which means there are nine eighth notes for each measure of the music. Slip jigs are also only performed by female dancers.
A final style of Irish Dance music is called a set dance. A set dance is sort of a party piece for a championship level Irish dancer. Typical to most Irish Dance styles, the right foot and left foot repeat in symmetry in the set dance.
But the third piece is a longer section of a specific choreographed tune where the dancer has the opportunity to display technical virtuosity.
Reels, jigs, slip jigs, horn pipes and set dances are all common kinds of Irish Dance music.