聖誕詩歌很多，但有二首是每年必唱的，否則缺少喜樂、和平、恬靜的氣氛。這二首歌就是「平安夜」與「普世歡騰」(Joy to the World)。
莫爾（Joseph Mohr, 1792-1848）出生奧地利薩爾斯堡，童年時是一個活潑的兒童合唱團的團員，1815年受封為羅馬天主教神父。
1818年聖誕節前夕，在奧地利的阿爾卑斯山谷中，有一座新建的小教堂。新到任的莫爾獨坐在教堂內，想到聖誕節來臨，教堂的風琴卻壞了，不能在午夜彌撒時，演奏原定的聖誕音樂，因此他必需寫下合適的詩歌作慶典之用。那天下午，他跋踄山谷探訪一個工人家庭，他們新生一嬰孩，看到他們貧窮的家境，使他聯想到救主的誕生。深夜他疲憊地獨坐在教堂，遠眺窗外，白雪皚皚暉映山壁，從悠靜的夜景中，他似乎看到當年救主降世的情景，於是他振筆疾書寫下了「平安夜」。翌晨，莫爾就興沖沖地去找他的好友格羅伯（Franz X. Gruber 1787-1863）。格羅伯是當地小學的校長，也是教堂的風琴師。他看了詩後，不禁歡呼：「這正是我們一直想要的聖誕詩，願我們的　神受讚美！」立刻他腦中湧出了一個美妙的旋律來配合這詩，他們興奮地練習著，格羅伯用吉他來伴奏，當晚他們的合唱深深地感動了會眾。
數月後，鄰村的樂師前來修理風琴，修畢請格羅伯試音，格羅伯就奏「平安夜」，樂師為美妙的音樂感動，央求格羅伯給他一份抄本。他帶回家鄉後，把它當作民謠教孩童們唱。在那村中有一個做手套的商人，他有四個女兒都具有優美的歌喉，常隨她們父親銷售手套四處演唱，漸成名為史氏四重唱（Strasser Quartet）。有一次她們被邀請至德王御前獻唱，德王腓烈第四聽到「平安夜」後，大受感動，他命令全國，今後慶祝聖誕時，都要把「平安夜」放在第一首；他又想找作者，但無人知曉，於是他派宮廷詩班長查訪。詩班長到各地圖書館查考，並向音樂家探詢，經年累月都不得要領。多年後，有一天詩班長路過薩爾斯堡時，聽到一隻鸚鵡在唱「平安夜」，覺得奇怪，後來想到附近有一座小教堂，鸚鵡該是從那兒聽到學會的，於是追蹤而去，找到了格羅伯，但此時莫爾業已逝世。

“Silent Night” (German: Stille Nacht, heilige Nacht) is a popular Christmas carol, composed in 1818 by Franz Xaver Gruber to lyrics by Joseph Mohr in the small town of Oberndorf bei Salzburg, Austria. It was declared an intangible cultural heritage by the UNESCO in March 2011.
The song was first performed on Christmas Eve 1818 at the St Nicholas parish church in Oberndorf, a village on the Salzach river. The young priest, Father Joseph Mohr, had come to Oberndorf the year before. He had already written the lyrics of the song “Stille Nacht” in 1816 at Mariapfarr, the hometown of his father in the Salzburg Lungau region, where Joseph had worked as a coadjutor.

The melody was composed by Franz Xaver Gruber, schoolmaster and organist in the nearby village of Arnsdorf. Before Christmas Eve, Mohr brought the words to Gruber and asked him to compose a melody and guitar accompaniment for the church service. Both performed the carol during the mass on the night of December 24.

The original manuscript has been lost. However a manuscript was discovered in 1995 in Mohr’s handwriting and dated by researchers at ca. 1820. It shows that Mohr wrote the words in 1816 when he was assigned to a pilgrim church in Mariapfarr, Austria, and shows that the music was composed by Gruber in 1818. This is the earliest manuscript that exists and the only one in Mohr’s handwriting.
In 1859, the Episcopalian bishop John Freeman Young published the English translation that is most frequently sung today. The version of the melody that is generally sung today differs slightly (particularly in the final strain) from Gruber’s original, which was a sprightly, dance-like tune in 6/8 time, as opposed to the slow, meditative lullaby version generally sung today. Today, the lyrics and melody are in the public domain.

The carol has been translated into about 140 languages.

The song was sung simultaneously in French, English and German by troops during the Christmas truce of 1914, as it was one carol that soldiers on both sides of the front line knew.

By Elvis Presley

Lyrics