You've been busy?
Hark the Herald Angels Sing, O Christmas Tree, Joy To The World, O Come All Ye Faithful, The Twelve Days Of Christmas, Silent Night, While Shepherds Watched and We Wish You A Merry Christmas?
Lovely. Well, as you've noticed, Christmas carolling is popular in the mid-19th century, especially because of well-known carols such as these. This is when most of the songs you are now singing were written. A book entitled, "Christmas Carols Ancient and Modern" has already been published in London, in 1833. This music book is bringing in a large interest in carolling and the playing of carols on the piano.
It was during the 12th century when St. Francis of Assisi first introduced Christmas carols to church services. But the tradition of singing while walking through neighbourhoods, just like you are doing, first emerged in Victorian England, as carols merged with Christian folk music.
Although we rarely see carollers in the 21st century, except perhaps in shopping malls, the custom of singing carols is still very popular during church services. And 150 years later the same songs are still being sung during the Christmas season.
Many famous artists will release Christmas albums in the 20th and 21st century, and they will become incredibly popular.
And now you know. Dress warmly!