Musical people know: producing sound is possible with nearly anything. Musical instruments are made of all sorts of materials, for instance, from ice.
A peculiar music festival takes places in the idyllic small Norwegian town of Geilo at the first full moon in January. Music enthusiasts encounter bands and solo artists here, much like at other festivals around the world.
But there is one distinctive difference: the instruments are made of pure ice. Xylophone, horns, harps and string instruments - all of them are made from ice from surrounding lakes.
Created by two Geilo residents, Pal K Medhus and Norwegian ice music pioneer and jazz musician Terje Isungset, the festival has taken place since 2006. The two were the first to experiment with instruments made of ice.
Nowadays, some 3,500 visitors come to the festival in Geilo each year.
The instruments - carved from blocks of ice with chain saws - are not created until the day of the concert. Then the fine-tuning of the instruments begins. The sound of the music can vary depending on the weather in that particular winter and the quality of the ice.
Even though the temperatures are far below zero, the instruments begin to melt quickly through their playing by warm human hands. The pitch also begins to change. So rather than much rehearsal, it's all about artistic improvisation on stage. The stage itself is likewise made of ice, as is the auditorium. Thus, music and nature melt together to form a unique symphony.
You'll find other unusual music instruments in our High Five ranking in the gallery above.