Ar Hyd y Nos (English: All Through the Night) is a Welsh song sung to a tune that was first published in Edward Jones' Musical and Poetical Relics of the Welsh Bards (1784). The most commonly sung Welsh lyrics were written by John Ceiriog Hughes (1832-1887). The melody was used by John Gay in The Beggar's Opera. It is used for LBW #281 for Reginald Heber's "God, Who Made the Earth and Heaven" and WOV #721 for Jaroslav Vajda's "Go, My Children with My Blessing".