O'Connor's in Fishstreet is the most famous of Doolin's three pubs and the one most associated with traditional Irish music. Sessions happen most evenings, and the standard of playing is consistently high — this is a real session where musicians play for themselves, not a performance put on for tourists.
The pub fills up fast in summer and standing room only is common by 9pm. The best strategy is to arrive early, claim a corner with a view of the musicians, and settle in for the evening with a pint of Guinness. The music typically runs from about 9:30pm and can go on past midnight.