Singers are seen during a rehearsal for the Song and Dance festival in Riga, Latvia, on July 4, 2013
Not your usual mothballed folk festival, a songfest more than a century old with a choir of thousands enjoys near mythical status for the role it played in little Latvia's battle for freedom.
The weeklong Latvian Song and Dance Celebration culminates Sunday when 12,000 people deliver old folk songs in pitch-perfect unison at a forest amphitheatre in Riga.
"It's an experience I would recommend to anyone!" conductor Romans Vanags says, gasping and dripping with sweat as he leads the giant choir in sweltering summer heat.
The songfest is an experience that takes place only every five years and boasts UNESCO World Heritage status.
Hopping down from the podium after a final rehearsal of "Saule, Perkons, Daugava" (Sun, Thunder, Daugava River) -- an unofficial national anthem for many Latvians -- Vanags was still on a high.
"I started doing this 20 years ago. Every time feels like the first time, yet every time is different. It's an amazing thing to feel the power of all those voices a capella," the 50-year-old tells AFP.
Vanags is one of an elite group of "dirigenti" or conductors entrusted with leading this highly important event of Latvian heritage, celebrating its 25th edition.
Since the 19th-century the festival has been one of the few constants in the turbulent history of the Baltic nation of just two million people.
Under Tsarist and then Soviet occupation, it was a lifeline for Latvian national identity.
"There is a war in which Latvia can win without weapons: choir wars," Culture Minister Zanete Jaunzeme-Grende said at the June 30 kickoff.
"In the 140-year history of the Song and Dance Celebration, we have become a superpower."
The festival started in 1873 as a rare opportunity for Latvians to use their own language in public under Tsarist Russian rule.
It quickly turned into a showcase for "dainas" or generations of peasant songs passed down by word of mouth.
After the communist revolution brought down the Tsar, Latvia declared independence on November 18, 1918, but the freedom was short-lived.
Alongside Estonia and Lithuania, Latvia was reoccupied by the Soviet Union in 1940, seized by Nazi Germany in 1941 and again taken over by Moscow in 1944.
"In most places people associate choirs with something religious or old fashioned," says Daina Rudusa, 26, who will sing at the grand finale, the culmination of three years of rehearsals.
"For us Latvians singing is cultural, historical, it is something we do on a daily basis," she explains.
"It is also historically important: during the years of the occupation choral music was a way to maintain a national identity, but also a means of creative resistance."
Under the Soviets, Latvians were allowed to sing in their native tongue but under the banners of Marx and Lenin.
The tone changed in June 1988 when the so-called "Singing Revolution" began in Estonia, as tens of thousands raised their voices in anti-Soviet anthems in Tallinn.
The sound of freedom then rang out in neighbouring Lithuania and Latvia, where long-banned national songs and flags reappeared in the 1990 edition of the festival as the Soviet Union crumbled, restoring independence in the Baltic states.
The national love affair with the song festival has boomed ever since.
Nearly 40,000 people or two percent of Latvia's population take to the stage -- a per capita equivalent of one million singers and dancers in France.
Another 100,000 people turn up to watch the show, which draws a total of 1,000 choirs and dance troupes from across the country.
Attending his fifth edition of the festival -- more than many Latvians manage -- Bernhard Bendel from Germany says he first took part in 1981.
"I had a Latvian girlfriend and she introduced me to it and its history. I love it and always come to Latvia specially for the festival," he tels AFP, adding it has inspired smaller copycat choirs in his native Limburg.