Some of the "coolest" music being made this time of year is heard at a mountaintop ice igloo concert hall in Lulea, Sweden, presented by the ICEstrument Orchestra.
The instruments are made of ice, and the music is played at subfreezing temperatures so the instruments don't melt. This is apparently not much of a problem at this northern latitude.
Tim Linhart came up with the idea of ice music 20 years ago and, judging from the appearance of the instruments, he has developed the concept into something that looks and sounds like art. Enough people are willing to sit in the frozen cave concert hall, togged out like they're going to the North Pole, to make this a recurring event.
As noted elsewhere, Linhart sees a spiritual connection to the idea of impermanence and the transitory nature of all things, since the instruments are, indeed, very impermanent. Some people may meditate looking at a burning candle for the same idea, but I guess the changing nature of water turning into ice and back again can convey a similar idea just as well.
Here's a National Geographic video for an intriguing look at how this music to "chill out" to is created: