ABC notation in Irish traditional music is a shorthand that uses letters A through G of the alphabet rather than placing note heads in a five-line musical staff.

Irish sessions are fun gatherings of musicians sharing tunes and conversations in a relaxed setting. They can be an important part of an area's Irish music community, passing along tunes and the tradition. While sessions can and do exist in private homes, today many sessions take place in pubs and other public spaces.

The Irish language word for "session" is seisiún. This article discusses tune-playing, although "session" can also refer to a singing session or a mixed session (tunes and songs).