Since the bass is the star of the show, you could cut a bit more low end from other instruments in the mix when they're overlapping in that dark opening.
Have you tried adding a little high EQ to the bass for the opening part, to help make it pop to the front? The piano doesn't stand out at all when the non-solo stuff happens as its doing the same as the guitar(s), so it all kind of gets a little indistinct.
