For a second, I almost thought the keyboard player in the other ones (ex, Battle Medley) was Motoi Sakuraba.
After a quick check, I discovered that it is, in fact, him! Turns out he joined with Revo to make Bravely Defaults music. Which, is a really cool thing for me. Motoi Sakuraba is one of my favourite composers. I tried re-learning keyboard because of him (and failed, turns out I can only play saxophone fff). And now I realize why I thought some of the stuff from this game had a feel similar to his work.
I don't know this guy, but if he helped making this OST as awesome as it turned out, I love him too.
I might even order this stupid DVD next month just to rip the audio from it....there isn't a proper version on the internetz besides this YouTube one.
In fact, he was waaaaaay worse.