They are instruments that make the sound of winter; the melodies of a frozen orchestra. Under a full winter moon, Norwegian musicians celebrated the season with instruments made of ice.
"Nature decides when this festival is going to be because of the full moon," festival creator Terje Isungset said at this year's festival in early February. "It decides the sounds of my instruments because of the quality of the ice."
"For most people in winter, [the snow and ice] has no value, it's just something you want to get rid of," Isungset said. "But I find a sound, when I find a sound, I try to work with it and create music with it."
Learning to make music from ice has been a journey of discovery for Isungset. It began when he was commissioned to perform at a festival in Norway in 2000 at a frozen waterfall.
"I didn't know what to do, but I had one idea, I wanted to make an ice harp," he said. "I discovered many things that I never imagined, sounds that I never imagined."
The ice is harvested from a frozen lake 25 miles north of Geilo. Ice cutters search for the clearest, cleanest ice. Using chain saws, they cut huge 600-pound blocks. Ice cutter Evan Rugg said they've seen some of the clearest ice ever this year. They've learned that the best sound comes from ice with no bubbles or cracks.
"This is probably the block with the best sound today," he said with satisfaction after heaving a block onto a sled behind his snowmobile. "You could see through it, and that makes a good sound."
Back at the outdoor concert venue in Geilo, ice sculptor Bill Covitz is busy carving instruments from the blocks. The Connecticut business owner -- Covitz's Ice Matters creates sculptures for weddings and events in the United States -- has found a new passion in Norway. This is his sixth year participating in the Ice Music Festival. Creating instruments from ice is just as challenging as playing them, he said.
"We experiment a lot," Covitz said, "always trying to come up with new sounds, new instruments."
The biggest test is seeing "how far we can push the ice before it breaks," he added.
For this year's festival, he fashioned two ice horns, an ice guitar and a five-string harp. But the most beautiful sounds come from the icicle-like chimes and what he calls the "iceophone" -- the frozen cousin of a xylophone.
"Sometimes ice is completely dead, and sometimes, it is fantastic, so it's really up to the winter," Covitz said.
Not every piece of ice has music, Isungset said. "I work mainly on pure water like this, and I search for the soul of the ice and for the ice pieces that can actually sing," he said.
"It is really hard to make music on ice and to work with ice. And what we do is nearly impossible."
To make hollow instruments such as the horns, Covitz carves two identical blacks. Once the insides are hollowed out, he glues them back together with -- what else? -- water. "It is amazingly strong," he said. "Once it is frozen, it holds together like when it was the original piece of ice."
Don't expect the ice guitar to play Top 10 rock 'n' roll tunes any time soon, Isungset said.
"The idea is to try and make ice music," he said. "I mean music that exists because of the sounds of ice.
"Because the sound of the ice changes with time and temperature, the music is always improvised. While rhythm may be repeated, no piece ever sounds the same."
And what exactly does ice sound like? "It is impossible to compare to anything," Isungset said.
Using ice's low frequencies, he creates music that is rooted in traditional Norwegian folk, but with international influences.
Performing with nature's vital resource is "a great honor," Isungset said. "These instruments are not mine, I just borrow them from the earth. I give them back after each use."