So what took so long? Well, about two and a half rejections from Apple. Odd number, eh? Let me briefly explain.
A few weeks after "Music Quiz 3D" was first submitted for review, it was rejected for a problem unrelated to the app. I had listed the term "iTunes" as a search keyboard. Listing the names of other apps is not allowed, but it didn't occur to me that "iTunes" might fall under that rule. It did occur to Apple.
No biggie. We resubmitted the app right away (even though the app was unchanged) and got ready to wait another three weeks. Four weeks. Five weeks. What the heck!? Checking on the app revealed that it was rejected, but we had never received an e-mail informing us of the rejection. But wait, did we really submit it the second time. There is no log to verify this, so maybe the fault was on our end. We resubmitted it again and started waiting.
At this point a very nice and helpful person from Apple called to say, essentially "Why did you resubmit the same app that we just rejected?" After a pleasant, but long, conversation all became clear. We had resubmitted the app the first time, and Apple did reject it a second time, but while they drafted an e-mail to us, it never got sent. The person from Apple was very apologetic, helped me understand why it was rejected the second time (an edge case I had never seen before), and encouraged us to modify the app and resubmit.
Well, the third (?fourth?) time's the charm. "Music Quiz 3D" is in the wilds of the iTunes App Store ready and waiting to entertain and amuse you. Enjoy!