Fado is also an Irish-language (Gaelic) word meaning "a long time ago". Indeed many Irish folk stories begin "Fado, fado, fado...", meaning "once upon a time".
The Irish storytelling tradition is intrinsically linked to the Irish language, and although it has waned a lot with the decline in the usage of the Irish language, a vibrant storytelling tradition still remains, particularly in those areas of Ireland where Irish is still fluently spoken. Beginning a tale with "Fado" is very traditional in setting the tone which will allow all kinds of tales of magic and mythology to flourish. Very much like prefacing a story with the disclaimer "a long time ago, in a place far, far away...". Fado is an important literary device in the Irish storytelling tradition.