The famous Christmas song that inspired the defenders of Ukraine

Pokrovsk in eastern Ukraine is the birthplace of one of the world's favorite Christmas carols.

But there is little sign of Christmas in town this year. Just a dusting of snow on deserted streets and skeletal buildings – and the constant sound of heavy shelling.

Pokrovsk is Russia's next target. His troops are now less than two miles (three kilometers) from the center of the city.

And it's not just buildings and homes that are destroyed. Ukraine accuses Russia of trying to erase its cultural identity as well – including its associations with the well-known song.

Most of Pokrovsk's population has already fled. Gas has been shut off and many homes are without electricity and water. Those who remain, like 59-year-old Igor, are only scrambling to find the bare necessities. He says it's like living on a powder keg – you never know when or where the next shell will land.

Oksana, 43, says she is too scared to leave her home, but goes out during lulls in shelling to find wood and coal to keep warm.

She told me she hoped Ukraine's armed forces could hold the city, but thought that was unlikely. Pokrovsk, she says, will probably fall.

The city has already prepared for the worst. The statue of its famous composer Mykola Leontovich has now been removed. The music school that bears his name now lies buried and empty.

Leontovich may not be well known in the West. But the tune he composed is known around the world – with its bell-like vocals. Leontovich is believed to have written the early scores of the composition, based on a Ukrainian folk chant, while living and working in Pokrovsk between 1904 and 1908.

In Ukraine it is known as Generous. To most of the world, it became known as Carol of the Bells after American composer Peter Wilhousky wrote English lyrics for the song. The use of the tune in the Hollywood film Home Alone helped boost its popularity.

Victoria Ametova calls it “a masterpiece – the signature song of Pokrovsk”. And until recently, she taught music in the city, at the school named after Leontovich.

She has now moved to the relative safety of the Dnieper. This is where many of Pokrovsk's former residents still try to keep the memories of their former home alive.

Beneath Leontovich's salvaged portrait, Viktoria watches as 13-year-old Anna Hasic plays the familiar chords of the Christmas carol on the piano.

The Hasich family fled Pokrovsk this summer. But they are determined not to forget the place they still call home. Anna's mother, Yulia, says she is happy to see her daughters practicing Shchedrik. “We will not forget the history of our city,” she says.

For Anna, the melody brings back memories. “When I dropped her off at home, she seemed happy. It reminded me of winter and Christmas,” she says. “Now it's more of a sad song for me because it reminds me of home and I really want to go back.”

But for a Ukrainian military band, Shtedrik has become a song that inspires resistance. They even play it in the trenches – using guns as makeshift tools.

They may be musicians, but their commander reminds me that they are soldiers first and foremost. All have spent some time on the front lines. Col. Bogdan Zadorozhniy, head of the orchestra and its conductor, says the song helps to lift soldiers' spirits. “These beats and rhythms cheer up the guys on the front line and inspire them to fight,” he says.

Roman, 22, uses a rocket launcher casing filled with rice to shake vigorously in time to the music. Shtedrik, he says, is “the pride of our country, it's freedom, it's in our souls, I get goosebumps from this song.”

Colonel Zadorozhny says Shtedrik shows that Ukraine is a civilized nation that is now at war and struggling for its identity.

Pokrovsk may fall into Russian hands. But its people are doing everything they can to preserve their culture and identity.

The director of the Pokrovsk Historical Museum, Angelina Rozhkova, has already rescued and transferred most of his valuable possessions to safety – including artifacts from Leontovich's life in Pokrovsk.

Russia, she says, doesn't just want to take Ukraine's territory — “It wants to destroy our culture and everything that is precious to us.”

Angelina says the people of Pokrovsk understand they may never return, “but our hearts and souls don't accept that.” So they do everything they can to preserve the past. The new motto is “preservation and saving equals profit”.

It's hard to say you're winning when your city is destroyed. But her people, like Leontovich's music, show extraordinary endurance.

Leontovich's life ended abruptly in 1921 when he was shot dead by a Soviet agent. His composition became a symbol of the struggle for independence of Ukraine. It still is.

Additional reporting by Hannah Chornous and Anastasia Levchenko