"She Moved Through the Fair" (or "She Moves Through the Fair") is a traditional Irish folk song, which exists in a number of versions and has been recorded many times.
The melody is in Mixolydian mode. John Loesberg speculates: "From its strange, almost Eastern sounding melody, it appears to be an air of some antiquity," but he does not define its age any more precisely. It has been found both in Ireland and in Scotland, but scraps of the song were first collected in County Donegal by the Longford poet Padraic Colum and the musicologist Herbert Hughes.
The lyrics were first published in Hughes's Irish Country Songs, published by Boosey & Hawkes in 1909.
In a letter published in The Irish Times (22 April 1970) Colum claimed that he was the author of all but the final verse. He also described how Herbert Hughes collected the tune and then he, Colum, had kept the last verse of a traditional song and written a couple of verses to fit the music.
One verse was not included in the first publication: Colum soon realised that he had not put in the poem the fact that the woman had died before the marriage, and so he wrote the verse that begins: "The people were saying, that no two were e'er wed, but one had a sorrow that never was said ..." and sent it on to Hughes, too late for publication in that particular collection. This extra verse was subsequently published in other collections, along with the other three verses. The lyrics were also published in Colum's collection Wild Earth: And Other Poems (1916), though their traditional origin is not mentioned there.
No earlier version of the three verses written by Colum has ever been found, so there is little doubt that he is the author of those three verses.
The traditional singer Paddy Tunney relates how Colum wrote the song after returning from a literary gathering in Donegal with Herbert Hughes and others. Tunney suggests, however, that it would be more accurate to say that Colum simply added additional lyrics, not the melody, to an original traditional song that by then had generated many variations throughout Ireland.
Tunney himself collected one version from an Irish singer called Barney McGarvey. This version was called "I Once Had a True Love". The opening four lines are reminiscent of "She Moved Through the Fair" and the second four lines are unmistakably similar.