This is a wonderful... um...
fantasia, I'll call it for now, but my only problem is is that almost the entire solo parts consist of never ending arpeggios. Are you planning on any revisions to the solo part? Because I do believe that adding a "second subject" for the solo part would make the solo part more melodic and not so repetitive. Hey, I just sparked an idea: why not add a second fugue (or contrapunctus) in the middle of the piece? Bach's
Triple Concerto in A Minor employs this, and it sounds very well.
This would sound very well when performed by an authentic performance group.
Well done.