WILLIAM BRANGHAM: From "Silent Night" to# "Jingle Bells," Christmas carols are some## of the most familiar and beloved songs# of the season, and some of the oldest.

Stephanie Sy explores why, even as# popular music changes with the times,## these classics have endured.

STEPHANIE SY: To help us dig into why# Christmas carols have stood the test## of time, I'm joined by Ariana Wyatt,# a professor of voice at Virginia Tech.

Ariana, it's great to have you on the "News Hour."

There are very few things that# haven't changed over the years,## and Christmas carols are one of# them.

In fact, as I was reading,## I understand that some of them date back 2,000# years to the birth of Christ.

Is that right?

ARIANA WYATT, Professor of Voice, Virginia# Tech: It's really remarkable, in fact,## that our first Christmas carol is# really proclaimed in the Gospel,## the "Angels Hymn," or "Gloria in Excelsis# Deo," which is a carol that we sing today## in many different versions and# have over the last 2,000 years.

STEPHANIE SY: I read that that's because# angels were viewed as biblically sort## of singing, that that was a biblical# interpretation of what was happening.

ARIANA WYATT: Yes, that's correct.# Scholars interpret that saying as singing.

And there's a lot of other references# to singing and praising with music,## with song in the Gospel.

So it makes sense# that the angels would have been singing that.

STEPHANIE SY: My favorite Christmas carol is# "O Holy Night."

And there are other carols## that start with this expression, O, right?

O,# come let us adore him.

Talk about the O carols.

ARIANA WYATT: Yes, it's really a fun thing.

So, in the eighth century, they made in the# liturgy a series of antiphons that were in## preparation for the birth of Christ.

So# they were during the period of Advent.## And there were seven specific# ones that led up to December 24.

So the last would be performed on December 23.# And they all started with O, O, and then a name## for God.

So, you had seven of them.

And the last# was "O, Emmanuel," or "O Come, O Come, Emmanuel.

"## And it's really interesting because, if you# reverse the order of the Latin of all of those O,## name for Christ, all seven, it spells ero cras,# E-R-O C-R-A-S, which means "I will come tomorrow."

STEPHANIE SY: Now, speaking of# the Latin, in the Middle Ages,## not a lot of people were speaking# Latin.

How did it become accessible## when Latin itself was not particularly# well-known at the time of these carols?

ARIANA WYATT: So it wasn't until the 12th century# when Saint Francis of Assisi in Italy started to## introduce the vernacular into the Christmas# story.

And so he would take these Christmas## hymns and put the verses in the vernacular,# which would have been Italian where he was.

And then the choruses were -- remained in# Latin.

And that allowed people to start## to connect with the story.

So, previous# to this, these hymns were not popular.## They didn't connect with them.

They# didn't understand what the story was.

STEPHANIE SY: Do we know anything about# the melodies and how they have evolved?

ARIANA WYATT: We assume that some of these# melodies date back to celebrations about## the winter solstice, which predate# Christianity.

And so they would take## these folk tunes and they would put on new# words that were around the Christmas story.

And they are gradually put into the repertory# and passed down through oral tradition,## both by just singing to your own children,# but also by groups of traveling musicians## who would go from town to town and# kind of sing these various songs.

STEPHANIE SY: That's extraordinary.

Speaking of speaking to children,# I used t.. my babies as a lullaby.

Is "Silent# Night" one that dates back pretty far?

ARIANA WYATT: It's actually# one of the more recent ones.## Recent is a subjective term when we're# talking about 2,000 years of history,## of course, but it dates to 1818,# and it was composed in Austria.

Then it was brought to the United States# in 1839 and performed for the first time## in New York City at Trinity Cathedral.

And from# there, it kind of took on a world of its own.## There's a great story of the Christmas truce of# 1914 during World War I, where German and American## troops sang that hymn together from across# the trenches in their respective languages,## because it was one of and remains# one of our shared Christmas carols.

STEPHANIE SY: World War II also gave us some# really emotionally powerful Christmas songs.## What was happening in America at that time# that led to songs like "White Christmas"?

ARIANA WYATT: Yes, there's two large things.

First, we have the invention of recorded sound.

FRANKLIN DELANO ROOSEVELT, Former President of the# United States: A date which will live in infamy.

ARIANA WYATT: That was a huge change to music# and how music is transferred and shared across## continents, really.

And so we have for the# first time the ability to share music out## over the radio, share music that can# be purchased and listened to at home,## which is really remarkable and was --# really changed everything at the time.

But, also, we have two major World Wars that# happened in the 20th century.

And as a result## of that, after World War II, we have a real# economic boom in the United States.

And so we## see a new genre of Christmas music emerge# that is really a contemporary, commercial## Christmas music.

And it has legs because we# can record it and then we can broadcast it.

The first one that we really# look to is "White Christmas,"## which was broadcast for the first time# on the radio on Christmas Day in 1941,## which was just 18 days after Pearl Harbor.

And,# of course, that song is built in nostalgia,## is built in hope for Christmases future,# in nostalgia for Christmases past.

And, of course, the nation was reeling, as was# the world at the time, in the middle of a of a## World War.

And it really spoke to people, which# is why it continues to speak to people today.

STEPHANIE SY: That is Ariana# Wyatt with Virginia Tech.

Ariana, thank you so much and happy holidays.

ARIANA WYATT: Happy holidays.

Go hear some music.