City fountains became impromptu rehearsal spaces this weekend as yodelers at a festival in Basel, Switzerland, squeezed in last-minute practice while cooling off during Europe’s June heat wave.

At one fountain, a folk band dipped their toes in the water on Saturday, as festivalgoers clapped along or cooled their hands under the flowing stream.

From Friday to Sunday, singers and alphorn players filled the streets and spontaneous bursts of yodeling echoed through restaurants, where diners initially reacted with surprise before joining in.

In Petersplatz, in central Basel, seamstresses remained on call throughout the festival to repair the traditional Alpine folk costumes worn by participants in case of emergency.

This year, however, it was the fountain rehearsals that became the festival’s defining image, as the city battled record temperatures of around 39 Celsius (102 Fahrenheit).