This 14 October 2020 Swiss German video from Schwyz canton says about itself (translated):
Our isolation ward for COVID patients fills up more every day and the proportion of patients requiring ventilation is increasing. …
Translated from Dutch NOS radio, 15 November 2020:
Yodel concert turns out to be superspreader
In the Swiss canton of Schwyz, the number of coronavirus infections has increased sharply after two yodel concerts. About 600 people attended those concerts at the end of last month. Face masks were not required, though those present were asked to keep their distance from each other.
Nine days after the performances, several visitors turned out to be infected and that number has now increased to 1,238 cases of infection that can be directly or indirectly related to the concerts. Half of the people who take a test turn out to be positive. According to a Swiss doctor, the explosive increase in the number of cases in Schwyz is “one of the worst in Europe“.
The yodellers probably infected the public. Shortly after the concert it turned out that some yodellers were infected with the virus. They probably spread the virus to the public with their singing.