From Lady Wilde, Ancient Legends of Ireland, page 268.
here was a girl in one of the villages that could see things no one else saw, and hear music no one else heard, for the fairies loved her and used to carry her away by night in a dream to dance with the fairy chiefs and princes. But, above all, she was loved by Finvarra the king, and used to dance with him all night till sunrise though her form seemed to be lying asleep on the bed.
One day she told some of her young companions that she was going that night to a great fairy dance on the rath, and if they chose she would bring them and put a salve on their eyes so that they could see wonders.
The young girls went with her, and on coming to the rath she said--
"Now put your foot on my foot and look over my left shoulder, and you will see the king and queen and all the beautiful lords and ladies with gold bands round their heads dancing on the grass. But take care when you see them to make no sign of the cross, nor speak the name of God, or they will vanish away, and perhaps even your life would be in danger."
On hearing this the girls ran away in fear and terror without ever using the spell or seeing the fairies. But the other remained, and told her friends next day that she had danced all night to the fairy music, and had heard the sweetest singing, so that she longed to go back and live for ever with the spirits on the hill.
And her wish was granted, for she died soon after, and on the night of her death soft music was heard floating round the house, though no one was visible. And it was said also that beautiful flowers grew on her grave, though no hand planted them there, and shadowy forms used to gather in the moonlight and sing a low chant over the place where she was laid.