A Christmas carol (also called a noël) is a carol (song or hymn) whose lyrics are on the theme of Christmas, or the winter season in general and which are traditionally sung in the period before Christmas and celebrate the birth of Jesus Christ.
Traditionally, carols have often been based on medieval chord patterns, and it is this that gives them their uniquely characteristic musical sound. Some carols like "Personent hodie" and "Angels from the Realms of Glory" can be traced directly back to the Middle Ages, and are among the oldest musical compositions still regularly sung.
Though many Christmas carols were written prior to the 20th century, several modern compositions have been written in more recent times. Many of the carols written by Alfred Burt are sung regularly in both sacred and secular settings, and are among the more well-known modern Christmas carols.