Children of Bodom's Alexi Laiho was joined by 100 other guitarists at the Helsinki festival over the weekend for a special performance dubbed "100 Guitars From Hell" featuring guitarists from around the globe shredding their heads off at Senate Square in Helsinki. More info on the project can be found here. There is a mini-doc in this video about how everything came together, just scrub to about 20 minutes in the video.
Listen to Children of Bodom's new single here.