Carols were originally associated with dancing, not singing, and Christmas hymns have always been Christian sacred songs.
Nowadays, the terms "Christmas carols," "Christmas hymns," and "Nativity songs" are used interchangeably. The history of Christmas music comes a long way. The word "carol" originally referred to a circle dance, "carola," performed without being sung.
When words were added, they were used only as accompaniment to the dance movements. Carols were derived from secular, pagan sources. Greeks and Romans had used them in their plays, festivals, weddings, and birthdays.
In the case of the first Christmas hymns, they were always aligned to Christian singing, sung to the melodies of Jewish temple hymns and psalms. Hymns of early church were about Christmas, used as part of worship service. As the church struggled against the influences of pagan customs, carols were strictly prohibited from sacred services, but outside the church, Nativity carols flourished.
Saint Francis of Assisi is credited with bringing carols into the formal worship of the church. In 1223, Francis was conducting Christmas services at Grecchio, in the province of Umbria. Presenting the concept of God's incarnation to his parish, on Christmas Eve, he borrowed some farm animals, collected the trapping of a stable, and placed a statue of the infant Christ in a manger filled with hay.
In a cave near the castle of Grecchio, he re-created the setting of the first Christmas night and conducted a midnight Mass. The friars composed and sang new joyful songs more like carols than hymns, to accompany the tableau. The way was opened for the church and carols to become reconciled.
Carols enjoyed further development through connection with the mystery plays of the Middle Ages. A complex of pageantry, piety, and song, the mysteries were dramatizations of biblical stories, presented with church festivals. A number of the medieval carols have been preserved in manuscripts.
Strolling carolers at Christmas are part of a long tradition that goes back through the beggars of the Middle Ages singing carols to seek alms or free portions of food and drink. In England, Yule serenaders known as 'Waits,' were rewarded with an invitation to enter the warm house and have a cup of Wassail (hot spiced ale or wine).
The Protestant Reformation reduced sharply secular Christmas observances. The German chorales of Luther and Bach brought the ceremonies back into the church, tying music closely to religious texts. Protestantism asked that Christmas songs avoid secular subjects and remain reverent.
Joyful hymns, however, were welcomed, provided they do not stray from the scriptural sacred context. Protestant congregational singing led to widespread familiarity with Christmas hymns, and the combining of folk melodies with sacred words increased in popularity.
The rise of Puritanism brought the greatest opposition to carols, and to the entire tradition of Christmas. In 1645, observance of all festival days, including Christmas, was abolished by Crowell's Parliament. During the 12 years ban, the Middle Ages carol faded in England. The United States, closely allied with Puritanism, restricted itself to singing and writing hymns. Interest of carols in other countries also waned.
In recent years, English-speaking people have become more aware of the rich musical heritage of Christmas from other countries, adding to the joy of Nativity to offer adoration and excitement to the Christ child in the manger.
The International Book of Christmas Carols, W. Ehret and G. K. Evans, Stephen Greene Press, Vermont (1980)
Victorian Songs and Music by Olivia Bailey, Caxton Publishing (2002)