High in the Alps, the resort of Davos has played host to the Swiss Federal Yodelling Festival, a three-yearly magnet for lovers of mountain folk music and the region's centuries' old traditions.
"It's all in the technique," said Roger Bider, 35, as bystanders applauded his eight-man group's spontaneous performance on a railway platform.
"You flip between singing from your head and your diaphragm," said Bider, one of two yodellers with then remainder of the team providing a bass-voice backing.
Known internationally for the annual World Economic Forum gathering of business and political leaders, this is the first time Davos is hosting the festival.
The national event, which was wrapping up yesterday began in 1924 and draws 10,000 participants and 100,000 fans.
While the events have juries, there are no prizes, beyond respect. But for many, yodelling is about more than just music.
"You get hooked," explained Paul Mettler, 62, of the Swiss Yodelling Association, which supervises the event.
"There's also the camaraderie. At events, you meet people you know, and make new friends too," he said.
Most participants are from Switzerland's majority German-language areas, whose guttural dialects bemuse outsiders.
Traditional songs include lyrics in dialect but tell stories of love and hardship.
Other musicians are mixing traditional Alpine music with new sounds.
Sonalp, a group from the cheese-making Etivaz region in western Switzerland, are influenced by rap and world music, using alphorns, cowbells, accordions and fiddles, along with Australian didgeridoos.
"We meld Swiss folk with other styles," fiddle-player Guillaume Wahli, 36, said.
"We use yodelling a lot. Our stuff's quite well-received, albeit not by everyone."
Yodelling is not all Swiss. It is famed in Austria's Tyrol region, and variants are found along central Europe's mountain chains.