Rhythm in Irish music is very important, it's a dance music ! You'll need to have a strong rhythm but without overtake the melody, which is very subtle.
In irish music there is two families of rhythms:
Reels (4/4), hornpipes (2/2), polkas (2/4), flings (2/2),
strathspeys (2/2), set dances (2/2), highland (2/2)
Jigs (6/8), slip jigs (9/8), slides (12/8), hop jigs (3/4), valses (3/4), mazurkas (3/4)
Let us look at reels, jigs, hornpipes and polkas. All the examples of rhythmics are played with the Dmodal chord.s
These are the most common tunes in Irish traditional music. If you can count until 8 you can play reels ! Indeed to start, you just have to do go and back counting from 1 to 8 accentuating the first time (fig 1).
To play the off-beat you can do the same thing but starting on the third time (example in tunes menu).
Here is an example in video with Arty McGlynn on the guitar (DADGBE tunning):
You can play jigs with two different techniques (that also can be combined). The first one is to count from 1 to 6 doing go and back and accentuating the fourth time (fig 2). The second way is to play 1/2/3, and the third we'll be more light (fig 3). The last technique is more dynamic but more difficult. It's also very useful to play slip jigs.
A video with John McCartin (DADGAD) playing jigs with the 1/2/3 technique (start at 0:56 min) :
You can play hornpipes with a very swung rhythm. They are sometimes played fast or slowly, depending on the dancers. They can look like reels but they are actually very different ! Your rhythm needs to be jerky which gives the sensation of using lots of blows down (fig 4).
An example in this video with the band Danu playing a hornpipe and then a reel :
Polkas are very popular dances in Europe. In Ireland, there is a strong polka tradition in the South West of the country, in county Kerry and Cork, and especially in the Sliabh Luachra area.
There are many ways to play polkas, this is one of them, emphasis first and second time, 3/4 and 7/8 are play but lighter (fig 5). Sometimes you can play just the first time and then the offbeat (fig 6 ), you can also do some triplets (see tunes example in menu).
You can listen to different guitar players, each one having their own method: Steve Cooney, Tim Edey, Jim Murray Tommy O'Sullivan...
Here is a video with Jim Murray on the guitar (DADGBD tuning) :