I received a phone call from a professor today notifying me of admission and the funding offer. My application status has not changed on the website, but I was told the official paperwork would come soon.
I also applied to Duke and have not heard anything yet. Since they allowed writing samples to arrive up until January 26, I would think we still have a bit of time to wait. But I do not know for sure. Hopefully soon!
I interviewed at UC Davis (skype and phone with several faculty members) earlier in the month. I have not heard anything back yet. I am also a doctoral musicology applicant.
The schools where I have interviewed said to expect something about two weeks after they finish interviews. But I imagine this can vary. Congrats on your offer and good luck in the next few weeks!