Christmas Eve, 1914. In the British trenches, you smell mud and rot. Then across No Man's Land, you hear the German soldiers sing Stille NachtThe Christmas Carol Silent Night, originally composed in German in 1818 by schoolmaster and organist Franz Xaver Gruber. - the start of the Christmas TruceA spontaneous ceasefire on the Western Front during World War One. German and Allied soldiers stopped fighting and came out of the trenches to sing, exchange food and play football. .

March 2020. Italy is the first European country to lock down from Covid-19. Families gather on balconies to belt out the national anthem.

Seven-year-old Amelia shelters from Russian bombs in Kyiv. Underground, she sings Let It Go¹ while millions watch online.

To these spine-tingling musical moments, we add a recording of Hymn to NikkalNikkal was the "great lady," wife of the moon god, in the religions of the ancient Near East., the world's oldest known song. The band HeilungAn experimental folk band with members from Denmark, Norway and Germany. say they are "amplifying history" on a new album with tunes from ancient Rome and a 13th-Century Icelandic curse.

Archaeologists discovered Hymn to Nikkal in northern Syria on 3,400-year-old clay tablets. The song is dedicated to the moon goddess, with lyrics in the ancient language Hurrian and a tune for the Babylonian lyre.

Why does song affect us and could music save the world?

Research shows that when we sing together our body releases hormones² linked to pleasure. Singing also reduces the stress hormone cortisol.

Music helps "empathyThe capacity to understand and feel the suffering of others. and inter-cultural understanding," says psychologist Eric Clarke. It is a universal language.

Throughout history, stirring tunes have inspired change. From revolutionaries singing The InternationaleWritten in 1871 by French anarchist Eugene Pottier, the leftwing anthem has been adopted by revolutionary movements and political parties across the world. to civil rights activists performing Amazing GraceA Christian hymn written by the former slave trader John Newton in 1779. It became an influential and popular song of the Black civil rights movement in the United States..

But, says Neil Young, "the time when music could change the world is past". In 1970, the Canadian musician penned the anti-Vietnam War song Ohio³. Today, he thinks you should look to science, not music, to save us.

Sceptics say the problem with music is it doesn't last. After the Christmas Truce, World War One rumbled on for four more years.

However, it is a skill everyone can learn. Education expert Steven Demorest argues we are obsessed with the "talent mindset". Shows like American Idol and The X Factor promote the idea that some people are not musical. In reality, all infants are natural musicians.

Some scientists think our ancestors sang and then spoke, some 300,000 years ago when we evolved the voice box.

We have a superpower connecting us to people on the other side of the planet. And to our deepest past. It can change our brain chemistry and the minds of others, but can it make history?

Yes: When we sing and hear music, we communicate across languages and borders. Music appeals to the oldest and most human part of our nature. It unites us with a common purpose to achieve great things.

No: Money makes the world go round, not music. Singing and dancing make us feel powerful, but it is an illusion. The people who can save the world are leaders, politicians and multinational companies.

Or...Songs are not always a force for good. Lyrics can be racist, sexist and xenophobic. Some songs glorify and encourage violence and hatred of others. And strong emotions can silence rational thought.