In Dulci Jubilo

In dulci jubilo ("In sweet rejoicing") is a traditional Christmas carol. In its original setting, the carol is a macaronic text of German and Latin dating from the Middle Ages. Subsequent translations into English, such as J.M. Neale's arrangement "Good Christian Men, Rejoice" have increased its popularity, and Robert Pearsall's 1837 macaronic translation is a mainstay of the Christmas Nine Lessons and Carols repertoire. J.S. Bach's chorale prelude based on the tune (BWV 729) is also a traditional for Christmas services.

The original song text, a macaronic alternation of Medieval German and Latin, is thought to have been written by the German mystic Heinrich Seuse circa 1328. According to folklore, Seuse heard angels sing these words and joined them in a dance of worship. In his biography (or perhaps autobiography), it was written:

Now this same angel came up to the Servant (Suso) brightly, and said that God had sent him down to him, to bring him heavenly joys amid his sufferings; adding that he must cast off all his sorrows from his mind and bear them company, and that he must also dance with them in heavenly fashion. Then they drew the Servant by the hand into the dance, and the youth began a joyous song about the infant Jesus ...

The tune first appears in Codex 1305, a manuscript in Leipzig University Library dating from c. 1400, although it has been suggested that the melody may have existed in Europe prior to this date. In print, the tune was included in Geistliche Lieder, a 1533 Lutheran hymnal by Joseph Klug. It also appears in Michael Vehe's Gesangbuch of 1537. In 1545, another verse was added, possibly by Martin Luther. This was included in Valentin Babst's Geistliche Lieder, printed in Leipzig. The melody was also popular elsewhere in Europe, and appears in a Swedish/Latin version in the 1582 Finnish songbook Piae Cantiones, a collection of sacred and secular medieval songs.

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