For many folks, Christmas caroling is a traditional part of their holiday celebration. It is also one that is steeped in the tradition of the ages.
No one knows exactly when the first Christmas carol was written; the name "carol" actually refers to a circle-type dance that was accompanied by singing.
But St. Francis of Assisi is credited with bringing music into the Christmas celebration, with the Nativity plays that he put on in Italy in the 1220s.
Many of the plays were put to music, and while some of it was in Latin, much was also in the language of the audience, especially as the practice spread to other parts of Europe over the next century.
By the 15th century, carols were not just sung in church, but they started to be sung at homes and by wandering minstrels.
The tradition grew especially strong in England — at least after Cromwell's Puritans, who banned all church music, were removed from power. There were often official carol singers called "waits," who sometimes doubled as watchmen, and who would go house to house, singing for money or food.
In Victorian times, the first published collection of Christmas music appeared, gathered by William Sandys and Davis Gilbert, and the singing of carols rose another notch.
That tradition continues today. Keith Cerny, chief executive officer of Sheet Music Plus, a company that sells sheet music in all genres, is an avid proponent of the practice of caroling. "It's a great way to bring people together," he said in a telephone interview from his office in California.
Caroling is a good way to feel more connected with friends and neighbors, he said. "Singing is always fun, but singing informally gives you an even greater chance to share feelings."
Cerny's first big exposure to singing was as a boy soprano with the San Francisco Boys Choir. "We did a lot of traditional concerts, but at Christmas, we did other things. We went house to house, singing. It's always fun."
He also lived in Britain for a time and learned of the long tradition of caroling there.
The thing about caroling, he said, is that pretty much everyone can do it. "If you have singers who can sing two- and four-parts, that's ideal. But if you just go out and sing in unison, that's better than not going out at all."
As to what to sing, the sky's pretty much the limit. "The classic carols are always popular, but a mix is also fun." One of his company's bestsellers every year, he said, is the "Charlie Brown Christmas" song. "Josh Groban songs are always popular, and those by newer popular singers like Taylor Swift do well."
The company has sheet music for more than 34,000 Christmas songs and 4,000 carols, "so there's a huge, broad repertoire available," he said. And styles and arrangements change.
"I've sung 'Silent Night' for 35 years, but there have been so many different arrangements that it never gets tiring; it keeps fresh."
His all-time favorite carol is probably "I Saw Three Ships," which, he said, "has also been done in so many fresh ways."
Sharing the music by caroling is a special experience, he said. If you really want to get into the spirit of the season, plan a caroling party. "Christmas is such a special time of year," he said. And music is a big part of the traditions.