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", "Good King Wenceslas", and "The Holly and the Ivy" can be traced directly back to the Middle Ages, and are among the oldest musical compositions still regularly sung.

Compositions continue to be written that become popular carols. For example, many of the carols written by Alfred Burt are sung regularly in both sacred and secular settings, and are among the better-known modern Christmas carols.