Some interesting Easter eggs, apologies if people already know this.
Murray Gold is playing the piano onscreen during the final song.
That little old lady was only June Freaking Hudson! Costume designer on Dr Who, Blakes 7 etc.
Jeremy Limb, who played the composer killed by Maestro at the start, is the son of Roger Limb who was part of the radiophonic workshop and who scored Keeper of Traken and a bunch of Davison stories.
And finally, is this the most obscure An Unearthly Child link possible?
I, for one, missed all of those cameos, so thank you for pointing them out! I had a hunch the old lady was Someone and I knew I recognized the name Chris Waites and the Carollers from somewhere but I couldn't for the life of me remember where. Otherwise, I didn't suss onto anyone else, particularly the Strictly Come Dancing cameos.