I'm sorry that you feel you need to know what is written about you in those files. If you were having legal difficulties because of the notes (such as having lost custody of children,) then yes, it would be good for your attorney to have. The notes there are for the therapists to work from in order to guide you the way you need to go for healing. It's also for the codes used for the insurance company so they pay.
It is usually not a good idea to read all that is in there, and the basic information, such as what the therapist has your disorders listed as, can be heard from your T. There is always a possibility that you are suffering in a way you aren't ready to realize yet, and it could put your therapy back to the beginning if you are reactive.
The issue here is trusting - or rather not trusting- your T. That is what takes time, in therapy, to develop. Viewing your records now may cause great misunderstanding and upset, and maybe even cause you to leave therapy. That wouldn't be a good thing. So I caution you to figure out WHY you "need" to see your files.
You know, just because you have the right doesn't mean it's in your own best interest to do this.