What is Traditional Irish Music, really?

We are no longer calling it "traditional Irish" or "Celtic" music.  We are calling it traditional Atlantic dance music, which reflects the fact that it was born in Normandy and Norway in the 11th century, immigrated to England and Scotland, and eventually made its way with the Ulster Scots to the Appalachian Mountains in America, and to Nova Scotia in Canada in the 16th and 17th centuries.  

Atlantic dance music forms such as the Hornpipe became synonymous with clogging in the North and buck dancing in the south, evolving into "Old Timey" music before WWII and Country and Bluegrass in the 1950s.  In New England where dancing was outlawed by the the "Blue Laws" until the mid-19th century, after which there was an explosion of dance in the region and still can be found to this day.

The term "traditional" can be misleading when applied to Irish music, as it implies an unbroken lineage that simply doesn’t exist due to centuries of colonization and cultural suppression. Instead, what we now call Irish music is better understood as a dynamic, evolving art form shaped by both external influences (English, Scottish, European) and internal innovation by Irish musicians.

Given the historical context outlined—colonial suppression of Gaelic culture, the lack of documentation for pre-19th-century music, and the significant influence of English and Scottish traditions—it is reasonable to conclude that seisúns as we understand them today were not prevalent until the 20th century.

The modern concept of a seisún is closely tied to pubs, which became central to Irish social life in the 20th century. Pubs provided a space for musicians to gather informally, play tunes, and share their repertoire.

However, pubs themselves were not always welcoming to traditional music earlier in history. It wasn’t until the mid-20th century that pub owners began actively encouraging music sessions as a way to attract customers.

The advent of recording technology in the early 20th century allowed Irish musicians to document and disseminate their music more widely. This helped standardize certain tunes and styles, creating a shared repertoire that facilitated communal playing.

By the mid-20th century, figures like Seán Ó Riada and groups like The Chieftains played a pivotal role in popularizing Irish music both in Ireland and internationally. Their work helped legitimize traditional music and encouraged its performance in public settings like pubs.

The global folk revival of the 1950s–1970s brought renewed interest in traditional music across many cultures, including Ireland. This movement helped formalize seisúns as a recognized cultural practice, with musicians gathering regularly to play tunes in a structured yet informal setting.

There is no substantial evidence of organized, communal music sessions resembling modern seisúns before the 20th century. What little documentation exists suggests that music was played privately or in small, informal groups rather than in public venues.

The term seisún itself only gained widespread usage in the mid-20th century, reflecting the relatively recent emergence of this specific form of communal music-making.