"The Valley Lay Smiling Before Me (The Song Of O'Ruark, Prince Of Breffni)" is on Thomas Moore's Irish Melodies (hyperion CD; track 12; with sound lip). This CD also contains "The Pretty Girl Milking The Cows" (harp; track 23) from Bunting.

From
Thomas Moore's Irish Melodies:

THE SONG OF O'RUARK, PRINCE OF BREFFNI*
(Melody - "The Pretty Girl milking her Cow")
Thomas Moore, from Irish Melodies, vol. 5

The valley lay smiling before me,
Where lately I left her behind;
Yet I trembled, and something hung o'er me,
That sadden'd the joy of my mind.
I look'd for the lamp which, she told me,
Should shine when her Pilgrim return'd;
But, though darkness began to infold me,
No lamp from the battlements burn'd!

2. I flew to her chamber - 'twas lonely,
As if the loved tenant lay dead;
Ah, would it were death, and death only!
But no, the young false one had fled.
And there hung the lute that could soften
My very worst pains into bliss;
While the hand that had waked it so often
Now throbb'd to a proud rival's kiss.

3. There was a time, falsest of women,
When Breffni's good sword would have sought
That man, through a million of foemen,
Who dared but to wrong thee in thought!
While now - oh degenerate daughter
Of Erin, how fallen is thy fame!
And through ages of bondage and slaughter,
Our country shall bleed for thy shame.

4. Already the curse is upon her,
And strangers her valleys profane;
They come to divide, to dishonour,
And tyrants they long will remain.
But onward! - the green banner rearing,
Go, flesh every sword to the hilt;
On our side is Virtue and Erin,
On theirs is the Saxon and Guilt.

* [Moore's original note] These stanzas are founded upon an event of most melancholy importance for Ireland, if, as we are told by our Irish historians, it gave England the first opportunity of profiting by our divisions and subduing us. The following are the circumstances, as related by O'Halloran: - "The king of Leinster had long conceived a violent affection for Bearbhorgil, daughter to the king of Meath, and though she had been for some time married to O'Ruark, prince of Breffni, yet it could not restrain his passion. They carried on a private correspondence, and she informed him that O'Ruark intended soon to go on a pilgrimage (an act of piety frequent in those days), and conjured him to embrace that opportunity of conveying her from her husband she detested to a lover she adored. Mac Murchad too puntually obeyed the summons, and had the lady conveyed to his capital of Ferns." - The monarch Roderick espoused the cause of O'Ruark, while Mac Murchad fled to England, and obtained the assistance of Henry II.
"Such," adds Giraldus Cambrensis (as I find him in an old translation), "is the variable and fickle nature of woman, by whom all mischief in the world (for the most part) do happen and come, as may appear by Marcus Antonius, and by the destruction of Troy." - from Irish Melodies.

From The Fiddler's Companion:

PRETTY GIRL MILKIN' HER COW [1] (An Cailin Deas Cruidte na m-Bo). AKA and see "Pretty Maid Milking Her Cow," "The Valley Lay Smiling Before Me," "I Would I Were But That Sweet Linnet," "The Flower of All Maidens." Irish, Slow Air (3/4 time). A Dorian (O'Neill): G Minor (Kerr). Standard. AB (O'Neill): AABB (Kerr). As can be seen by the alternate titles above, this popular and large Irish tune family is the vehicle for numerous folk songs, and can be heard in slip jig and even reel form in dance tunes (see, for example, a polka version of the tune under "Pretty Maid Milking Her Cow."). Norman Cazden (et al, 1982) collected it in the Catskill Mountains (New York) as "The Green Mossy Bands by the Lea.," and discusses it extensively in his "Folk Songs of the Catskills." Other songs sometimes sung to it, he finds, are the lumbercamp favorite "Erin's Green Shores," "The Banks of the Little Eau Pleine." In Pennsylvania, it has been collected as "The Pretty Girl Milking Her Goat." Cazden also notes that the melody was used for "Llanarmon" (a Welsh hymn), a Newfoundland song called "The Blooming Bright Star of Belle Isle," an 1888 London music hall song written by Lady Dufferin entitled "Terence's Farewell," and many others. Thomas Moore set his text "The Valley Lay Smiling Before Me" to it. Kerr (Merry Melodies), Vol. 4; No. 243, pg. 26 (set as a jig). O'Neill (1850), 1979; No. 102, pg. 19. Maggie's Music MM107, "Music in the Great Hall" (1992).

PRETTY GIRL MILKIN' HER COW [2] (An Cailin Deas Cruidte na m-Bo). AKA and see "Pretty Maid Milking Her Cow." Irish, Jig (6/8 time) or Slow Air (3/4 time). A Dorian. Standard. AB. The tune is rendered in 9/8 time in the Roche Collection (appears as "Pretty Maid ...")./ Very similar to version #1. Hardings All-Round, 1905; No. 188, pg. 59. O'Neill (1850), 1979; No. 103, pg. 19.

PRETTY MAID MILKIN' HER COW [1]. Irish, American; Polka. C Major. Standard. See note for "Pretty Girl Milking Her Cow." AABB (Ford): AA'B (Carlin). Carlin (Master Collection), 1984; No. 281, pg. 158. Ford (Traditional Music in America), 1940; pg. 110.

PRETTY MAID MILKING HER COW, THE [2] (An Cailin Deas Cruidte na m-Bo). AKA and see "Pretty Girl Milking Her Cow." Irish, Air (9/8 time). A Dorian. Standard. AAB. The tune is rendered in 6/8 time in Harding's Collection (appears as "Pretty Girl Milking Her Cow"). Roche Collection, 1982, Vol. 1; No. 40, pg. 20.

The earliest record of the tune is probably "Calin deas scruidadh na mbo" [Cailín deas crúite ba mbó] in Edward Bunting, ed., A General Collection of the Ancient Irish Music, Vol. 1 (1796) [p. 54; the credit is to Arthur O'Neill]; the score is in Aloys Fleischmann, ed., Sources of Irish Traditional Music c.1600-1855, Vol. 1 (Garland, 1998, p. 619 [no. 3379]). The tune is not in The Ancient Music of Ireland (1840) by Bunting (Dover's reprint edition, 2000; and Fleischmann, Vol. 2, pp. 1055-1106).

~Masato