By the Middle Ages, wandering minstrels were traveling from hamlet to castle performing their carols. Later still, villages had their own bands of "waits." Waits were originally watchmen who patrolled the streets and byways of the old walled cities, keeping guard against fire and singing to while away the night hours. During the holiday season, the waits would include carols in their repertoires. Not everyone was delighted with this display of musical entertainment, however, and many townspeople complained, declaring they would rather get a good night's sleep than have somebody singing under their windows. Eventually the term was used to describe groups of musicians who sang and played at various civic events during the Christmas season.
The word "carol" derives from a Greek dance called a choraulein, which was accompanied by flute music. The dance later spread throughout Europe and became particularly popular by the French, who replaced the flute music with singing. Originally, people performed carols on many occasions during the year. By the 1600s, carols involved singing only and Christmas had become the chief holiday for these songs. Counted among the most favored of non-religious carols are "Jingle Bells" and "White Christmas," both of which first appeared as popular songs in the United States.