Little things you're surprised Who hasn't done yet

I am surprised Doctor Who has not done a full blown musical episode. I have not seen it yet but I know The Gunslingers has a few songs, but I think a full blown broadway style episode with big song and dance numbers would be amazing. Especially for a Christmas episode! They could finally bring back captain Jack since we know John Barrowman can sing😀Think of potential of the Doctor singing a balad of saving earth or a fun companion group number! Also imagine the villain song you could get!