Ar Hyd y Nos

Ar Hyd y Nos (English: All Through the Night) is a Welsh song sung to a tune that was first recorded 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), and have been translated into several languages, including English (most famously by Harold Boulton) and Breton. One of the earliest English versions, to different Welsh lyrics by one John Jones, was by Thomas Oliphant in 1862.

The melody was used by John Gay in The Beggar's Opera. It is also used in the hymn "Go My Children With My Blessing."

The song is highly popular with traditional Welsh male voice choirs, and is sung by them at festivals in Wales and around the world.

The song is also sometimes considered a Christmas carol, and as such has been performed by many artists on Christmas albums, including Olivia Newton-John and Michael McDonald, who sang it as a duet on Newton-John's 2007 album Christmas Wish. Cerys Matthews sang it solo on her 2010 album Tir.

Different English lyrics were written by Sir Harold Boulton in 1884 and set to the same tune.

In an alternate version, the second verse is substituted with:

Another alternate version features a more neutral, night song text:

Yet another alternate version of the second verse is as follows:

A. G. Prys-Jones wrote a more literal but still rhyming version:

The tune is also used in the hymn "For the Fruit of All Creation" by Fred Pratt Green. The first verse of Green's lyrics (used widely in the harvest season and at Thanksgiving) ends with these words: "For the plowing, sowing, reaping, silent growth while we are sleeping, / Future needs in earth's safekeeping, thanks be to God."

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