Music of the Spheres is cancelled. I've moved on to a different project, unrelated to FiM and not fanfiction whatsoever, and in doing so my muse has fled. For me to continue on with this story would be even worse than if I stopped now--the story would be awful, I would be sapped by it, and no one would be pleased with the results.
I think it's fairly certain to say that I will not return to write any more pony fanfiction. I apologize--but if you want to follow anything else I'm doing, my deviantart is MrBoltzmann.
Meanwhile, since I don't like putting good ideas to waste, I'm opening a Q&A just like the one I did with Dark Thresholds. Ask me any question you want about our plans for the story--but be aware that said plans are somewhat incomplete in places, and that some tidbits may require background information that could take a while to type out.
So ask away. I promise a good, candid answer for every question.