Perhaps more than any other country in the world, the history of the Baltic nation of Estonia is a story set to song. Whether under German, Danish, Swedish, or Soviet occupation, Estonians have long turned to music as a way of preserving some semblance of national identity amid foreign domination. The country’s massive song festivals, which date back to 1869, feature a choir of roughly 20,000 to 30,000 singers and have drawn audiences of more than 100,000 people—nearly a tenth of the population. But lately, as Estonia has opened up to the world, the world has been opening up the country’s music scene to diverse influences. Which raises a couple questions: Has Estonian music lost its essence? And, if so, is that something to mourn or cheer?

During the Soviet era, Estonia’s song festivals included plenty of Soviet propaganda, but they also offered Estonians an opportunity to celebrate their language and traditions. For the 1947 song festival—the first under the rule of the U.S.S.R.—the composer Gustav Ernesaks set an old poem, “Mu Isamaa On Minu Arm” (My Country Is My Love), to music. Estonians defied Soviet authorities and performed the song during subsequent festivals, and it soon became something of an unofficial national anthem. Other music was less overtly nationalistic: By writing songs ostensibly about Lenin’s sayings on freedom, composers like Veljo Tormis gave their music double meanings. The music expressed Estonians’ desire for self-determination and pointed out how the Soviet Union had failed to live up to the principles of its founders—all within the confines of communist censorship.

In the late 1980s, music was the mechanism by which Estonia split from the Soviet Union. During the “Singing Revolution,” large groups of people managed to organize for independence under the guise of gathering to sing. In June 1988, 100,000 Estonians gathered for five nights to sing protest songs until daybreak. Singing “Mu Isamaa On Minu Arm” at festivals “is our nation’s most glorious form of self-expression,” wrote the activist Heinz Valk that month. “A nation who makes its revolution by singing and smiling should be a sublime example to all.” The movement culminated in Estonia achieving independence, nonviolently, in 1991.

The song festivals, which occur every five years, still draw large crowds and nurture Estonian nationalism. “I think we were expecting 30,000 people singing at a baseball game,” said Maureen Tusty, an American filmmaker who produced the 2007 documentary The Singing Revolution with her husband James. “But it’s really the expertise of the choir—you’re just overwhelmed with voices and the power of the music. It’s a very visceral experience. You feel it in your gut.”