I also applied for the Musicology MSt and for Ertegun - hi! Hope to see you in October.
I don't have any more information than you re decision timelines, but from trawling through gradcafe etc it seems like it has historically varied a lot when people hear about both admissions and Ertegun/Clarendon, from the end of February to the end of March.
If anyone has any insights about the Ertegun interview in particular it would be greatly appreciated - what kinds of questions they ask, how long it lasts, the general vibe etc. I'm not great in interviews and so just in case I do get one, I want to be well prepared!
Best wishes for the wait and good luck x