...and what else?...a 'ghost choir' in relation to a stasi desk?...well, I know where you can find the 'ghost choir'...at scarlett's old haunting ground....remember the arched windows above that QD store?....go figure:

https://www.tumblr.com/video/mary2point5/179763512549/400/

GC for short, eh?...not to be confused with GCHQ....ha ha ha...