God rest ye merry, gentlemen
Let nothing ye dismay
Remember Christ our Saviour
Was born on Christmas day
To save us all from Satan's power
When we were gone astray
Oh tidings of comfort and joy, comfort and joy
Oh tidings of comfort and joy.
God Rest Ye Merry, Gentlemen was written by an Englishman in the 16th Century. Light and exuberant in tone, it was the peasants' response to the church's somber, dark Latin hymns. While at first it was sung outside of the church walls, it gradually gained acceptance within the church as well. In 1760, the carol appeared in print for the first time, set to an English melody. In 1843, God Rest Ye Merry, Gentlemen had the distinction of being the only carol in Charles Dickens' A Christmas Carol. By the late Victorian era, the song was the nation's favourite. (https://en.wikipedia.org/wiki/God_Rest_You_Merry,_Gentlemen)
English has evolved over the centuries and therefore the meaning of the title needs clarification. Today "rest" means to relax. However, back in the 16th Century it meant to keep. "Merry" means happy today, but back then it meant to be mighty. In other words, the title means God keep you mighty, men.
Bing Crosby recorded God Rest Ye Merry, Gentlemen on his White Christmas Album in 1942. Nat King Cole also recorded the carol on The Magic of Christmas album in 1960. To hear the Trans- Siberian Orchestra version, click here http://www.last.fm/music/Trans-Siberian+Orchestra/_/God+Rest+Ye+Merry+Gentlemen.