I love John Williams' Memoirs of a Geisha.
For once it seems like an American film composer for once listened to the actual source music of a different culture and attempted to preserve that tone over to the western ensemble.
Actually, I am not Japanese, I am Korean, but I know Japanese music as well.
One of the things that makes John Williams' score so "authentic" is its avoidance of lush harmonies. East Asian music never had any triadic harmonies as standard in western music, so Mr. Williams avoids its overt usage to not disturb the Japanese aspect of the score.
Mr. Clemmensen correctly points out the score's restrained character. That is the supreme characteristic of all Japanese music, the cool exterior that never lets emotions disturb it. Chinese music is lyrical, Korean music is emotional, but Japanese music is faceless, just like the masks of a Noh play.
However, the one cue that Mr. Clemmensen mentioned as "dissonant" is actually the only cue that contains genuine Japanese music: indeed, that is what authentic Japanese music sounds like. Now you know how much composers change the character of Asian music when they write their faux pas Orientalism! (think Hans Zimmer's score for Kung Fu Panda, which sounds all right for American people but is insufferable for me).
Before listening to this soundtrack, I think people who have true respect for music should go out of their way to listen to authentic Japanese music. After listening, you will see how much John Williams truly respected the music of a completely different culture.