About Sean Nós Music
Sean-nós is a specific style of unaccompanied singing in the Irish language. There are three main styles of sean-nós, corresponding to the three areas where Irish is still spoken as a community language; the Gaeltachtaí of Munster, Connacht and Ulster. Munster Gaeltachtaí include parts of Cork, Kerry, and Waterford, the Connacht Gaeltachtaí are on the west coasts of counties Galway and Mayo, and the Ulster Gaeltacht is entirely within county Donegal. It would not be correct to say that sean-nós is not practiced outside of these areas, but only that three distinct styles can be recognised. Singers from the Galltacht (English speaking areas of Ireland), and indeed from outside Ireland, may sing in one of the three styles, or may blend them, depending on where they learned. It has been my experience that speakers of a given dialect of Irish, whether or not they come from the region where that dialect is spoken, tend to stick to the style of sean-nós that corresponds to that region. Speakers of "Gaeilge Bl' Áth' Cliath" (the official standard taught in the schools) are more likely to mix the styles of singing. The most obvious difference between the styles, to someone not familiar with sean-nós, is between the Ulster style and the other two. Donegal sean-nós has been heavily influenced by Scots Gaelic song, which is much less ornamented than sean-nós. Donegal singers tend to keep a steady pulse throughout the song. The melody is presented with minimal ornamentation (for sean-nós, that is.) The Munster and Connacht styles can be more difficult to distinguish, unless of course one is familiar enough with Irish to recognise the differences in the language. Both styles are highly ornamented, both with the forms familiar to a traditional instrumentalist and with other more complex forms. Indeed, the melody in these styles can be hard for the learner to pick out at times. To my ear, the Connacht style seems to be less concerned with the integrity of the beat, particularly in slower songs. With this style, perhaps more than any other, it is almost essential that the listener have a good understanding of Irish to get the most out of the performance. The real beauty of the Connacht style is to me the way the performer connects the text to his interpretation of the melody. The Munster style is less directly familiar to me, but my limited experience leads me to believe that it has more attention to the pulse of the beat than in Connacht.
Quoted from Tomás Ó Canainn: Traditional Music in Ireland published by Ossian Publications, Cork (ISBN 0 946005 73 7).