It makes me feel terribly slow-witted to have listened to the Gael-Linn anthology of Gaelic songs recorded by women singers, for over a month, and to have just now noticed a musical detail.

Of the seventeen songs on the compact disc album, the first and the last, while not musically identical, have melodies that are eerily similar.
You would never know this to look at the index of song titles, for the excellent reason that the lyrics, on Song 1 and Song 17, are entirely different.   

Máire Ní Scolaí opens the album with "An Draighnean Donn," a Gael-Linn re-release of a recording made for RTÉ broadcasts.
Mary O'Hara sings "Róisín Dubh", without harp or any other accompaniment, from her live concert recording in Ireland's National Gallery, which was released on Gael Linn in the 1980's.

These two performances make an interesting pair of bookends to the extremely diverse voices, techniques, and repertoire collected on this compact disc (titled Amhráin Ghrá).