Just to tie in with the last thing I dumped online, today's musical selection is "Shima Uta" ("Island Song"). It's not a folk song, precisely; it was written by a group called The Boom in more modern times, and has been covered by a number of J-pop artists, including much squeakier people like Kuraki Mai. I'm told it was inspired particularly by the stories of lovers separated by the fighting of WWII.
Note that although this version has both English and Japanese subs, the Japanese subs do not match the singing. "Shima Uta" is written in the Okinawa dialect, which is recognizable as close to standard Japanese, but not quite close enough to be mutually comprehensible. Particularly audible are the phrases that end in …よ in the Japanese subs; they're using some other verb tense that I've never heard before, but sounds vaguely related to stuff in old literary Japanese. You can also hear ぬ for の, sometimes. There are other bits, but not so's you'd notice if you don't read kanji. After hearing this, I begin to wonder if some of Gackt's distinctive sound is actually the remnants of an Okinawan accent. It's difficult to completely submerge your natural accent when singing -- listen to Hugh Laurie on House sometime -- and Uchinaaguchi, and even Okinawa Japanese has a different accent than mainland Japanese, most notably a much rounder /u/-sound than the standard.
Also note that of the performers, Gackt seems to be the only one accustomed to full-production stage work. I have no idea who the ladies or the older gentleman are, but I'd bet they typically perform with minimal equipment and amplification. They have no trouble staying on track with one another in open air, but Gackt is used to wearing a monitor earpiece, and can't hear himself properly until he cups a hand behind his ear.