Mass yodelling at Jodlerfest

More than 15,000 professional yodellers are set to take part in the annual festival of the tradition Jodlerfest.

This June, the festival will take place in the Swiss city of Lucerne, featuring the talents of yodellers, alphorn players and flag throwers. There will also be smaller festivals and folk concerts.

Revellers dressed in traditional costume ensure Jodlerfest is a colourful affair that lasts into the small hours.

Yodelling originated in mountain communities as a means of long-distance communication across peaks.

It is a form of singing involving singing a single note which rapidly fluctuates in pitch at a very high volume. The technique works best in places where there is an echo, for example lakes, gorges or mountain ranges.

Different sounds or sequences of notes would be used to convey various messages, for example "I'm on my way over" or "come home for dinner".