A very popular and ancient Irish air.
A little history from Ceolas.org:
“The Queen of Irish Airs” maintains Francis O’Neill (1913). There are many versions of this ancient and celebrated air “of which Bunting’s and Moore’s are not among the best: they are both wanting in simplicity,” states Joyce (1909), who prints the tune as collected by Forde from Hugh O’Beirne (a Munster fiddler from whom a great many tunes were collected). He considers Forde’s version “beautiful…(and) probably the original unadulterated melody,” and adds that it is similar to the version he heard the old Limerick people sing in his youth during the 1820’s. Flood (1906) states it is probable the air dates from the year 1296 or 1297, believing it must have been composed not long after the Statute, 24th of Edward I, in 1295, which forbade those English in Ireland (who were becoming assimilated into the majority Gaelic culture) to affect the Irish hair style by allowing their locks to grow in “coolins.”
The original song, told from a young maiden’s point of view, berates those Anglo-Irish who conformed to the edict by cutting their hair, and praises the proud Irishman who remained true to ancestral custom (the Gaelic title “An Chuilfhionn,” means ‘the fair-haired one’).
The Irish Parliament passed another law in 1539 forbidding any male, Irish or Anglo-Irish, from wearing long or flowing locks of hair.
This piece was made even more popular in the 1990s by Michael Flatley (of Riverdance and Lord of the Dance fame). He called his arrangement Whispering Wind. Here it is as a concert solo in 1998 in Hyde Park, in the perfect moment of a summer twilight as the last traces of blue fade from the sky.