This is a traditional Irish song arranged by Lasairfhíona Ní Chonaola. It appears on her debut album An Raicín Álainn, released in 2002.
This is one of the most famous of the classic eighteenth-century love songs of the sean-nós style. The singer berates his deceased beloved for having abandoned him, but he nonetheless sings her praises with great eloquence (“you were a harp playing music before me on the road,” “your mouth is as sugar, as the new milk and the wine on the table”). Some versions of this song have as many as 45 verses!
Well, Úna Bhán, her real name is Úna Mac Diarmada, or úna MacDermott. She was a well-to-do, rich man’s daughter, and she fell in love with a man called Thomas Costello. And he was otherwise known as “Strong Thomas Costello.” And she lived in Mayo, and he lived about eight miles away from her. Well, this time she fell sick, for the love of Thomas Costello, and her father would have nothing to do with him. But she was so ill that they sent for him to come to her bedside. And while he was there, she got better, and better. And as she got better her father saw no more reason to keep him in the house, so he sent him away, still refusing to let him marry her. And he swore if he crossed a certain river called the Donoghue River, that he would never come back to the house no matter how ill or anything she got after he left. Well, he left the house, and he went into the river. And he put the horse he was riding back and forth in the river for a couple of hours, and still there was no call from the house for him to come back. So eventually he crossed over to the other bank. And the minute he was on the other bank, the father ran after him calling him back. But he had given his oath that he wouldn’t come after he crossed the river, so he went on his way home. And two days after, she died, and he came to the graveyard where she was buried, and he sang the lament over her grave, every night for a week. Eventually they found him dead on top of the grave.