The composer's a she. And her name is Yuki Kajiura. I personally liked her style of songs actually. Chants and everything. Mitsuda was great, but somehow I found his choice of vocals rather disappointing. It just didnt fit with Xenosaga I, imo. Yuki Kajiura's done more anime ost's than game, like Noir, Hack and Tsubasa Reservoir Chronicles.