Good first attempt.
Too many breaks though. But it's pretty good.
I'm a fan of the audio portal big time, much more than the flash, and i'm always eager to find orchestral pieces. I have to say as a first try i am incredibly impressed by this, as a first try. It does loop a bit and could do increasing the volume at places and changing it a bit as it is sort of looping itself.
8/10 for quality
5/5 for effect
Please contact me if you would like to use this in a project. We can discuss the details.