[6][5] Three of the carols ("An angel this night", "This is St. Stephen's day", and "The first day of the year") are taken from A Smale Garland of Pious and Godly Songs by Bishop Luke Wadding, a collection of the Bishop's original Christian poetry, which was heavily influenced by his close reading of Richard Crashaw and the other Metaphysical poets, which was originally published at Ghent in 1684.
Bishop Wadding, a Roman Catholic priest descended from the local Old English nobility, led and sought to rebuild the Diocese of Ferns during the aftermath of the Cromwellian conquest of Ireland and during the revived religious persecution of the Catholic Church in Ireland during the anti-Catholic show trials caused by the conspiracy theories Titus Oates, which heavily influenced Wadding's poetry.
[4] The singers consist of six local men, always including a member of the Devereux family, who traditionally divide into two groups of three and sing alternate stanzas.
Of the carols the first, usually titled "The Darkest Midnight in December", has been arranged by several composers such as Stephen Main,[12] Kelly-Marie Murphy,[13] Dave Flynn,[14] James Tanguay,[15] Mark Swinton,[16] and William Whitehead.
[20] In 2011, Aoife Clancy, Robbie O'Connell, and Jimmy Keane performed a concert in Unity, Maine which included selections from the carols.
[24] Musical quintet Ensemble Ibérica performed selections from the carols at St. Paul's Episcopal Church in Kansas City, Missouri in 2014 and 2016.
[25][26][27] In 2019, the Esprit de Choeur women’s choir featured Murphy's setting of the first carol at their concert "The Darkest Midnight in December", held in Winnipeg, Canada.
Joseph Ranson published the words and surviving music of the Kilmore Carols in The Past, the journal of Wexford's Uí Cinsealaigh Historical Society.