Anyone who makes the trek out to the mountains of Naeba for the annual Fuji Rock Festival will tell you two things, apart from that they had a great time: It rains, and it's clean for an event of such enormous scale. But it's not completely sterile.

"I don't like it when things are too clean," says president of Smash and festival-founder Masahiro Hidaka, with his trademark dry humor. "There are countless types of people out there, so it makes me feel sick to my stomach when things are too strict."

Nevertheless, the event that he founded in 1997 is known to be the cleanest large-scale music festival in the world. And for good reason, too. Punters will be hard-pressed to find the garbage that is so prevalent on the dance floors and mosh pits of many of the world's major musical gatherings. That's because a large portion of it — as well as solar energy — is used to power three of the stages as bio-diesel energy: The New Power Gear (part of the Gypsy Avalon field), Mokudo Tei and The Field Of Heaven.