Starting out as a three day festival in 1978 to commemorate Turlough O'Carolan, harper and composer, who is buried in Kilronan Cemetery, this festival and summer school is now a week long international celebration of traditional Irish music, harp, song and dance.

In 2013, the year of The Gathering, the festival looks forward to welcoming those friends and relatives from overseas who have left the area and are returning to Keadue to enjoy the festival's 35th anniversary. In the preceding days, the O'Carolan Summer School takes place and includes classes, ceilí, concert, recitals and music sessions. Students can avail of tuition in a range of traditional musical instruments, traditional singing, set dancing and sean nós dancing. The festival, which starts on the final day of the summer school on August 2, continues over the bank holiday August weekend with concerts, an acclaimed international harp competition, festival lecture, music sessions, the "must see" unique door dancing competition and many more events.

This festival/summer school is held under the auspices of Comhaltas Ceoltoiri Eireann. Keadue, an award winning village in the National Tidy Towns competition, is situated in Kilronan one of Ireland's hidden areas of outstanding beauty and heritage on the shores of Lough Meelagh, in the shadow of the Arigna mountains and the Arigna Mining Experience