Patchface Speaks Raven

When you say "no one" do you mean not another person or Jaquen/HoBW/No One?  I think the Green Men should be on the list too.

I think so. Maybe even Quaithe, The Great Other & R'hllor? Or is that too many choices?

Lord Leyton Hightower and the Mad Maid should be in there, as well as anyone who might be holed up in that tower with them.

I like this as a crackpot guess. Otherwise, why are they in this story.

I would be totally cool with that. Do I need to add the poll? Can you do it?

I read it as the song was a recent development. Here's my reasoning; Shireen has an affection for Patchface, it is established as the main reason he is kept around. Shireen does not like the song. If he had sung that little ditty for years then I find it hard to believe that Shireen would develop such an affection for him, therefore the song must be a recent addition to his repertoire.

So despite my initial call of BR as the spymaster I am now less sure. The reason ? This:

We are told that the ravens are "pure bred white ravens of the Citadel". They are no "common albinos". In short, they are most assuredly the Citadel's creatures. When we look at some of the descriptions of Walgrave then he kinda sounds like how Haggon (was it Haggon?) described skinchangers that spent too much time in the skin of birds. Guys, Walgrave is a skinchanger. Me nem nessa.

Feel free to just slap it on there as soon as you feel we have enough candidates.
I'm always genuinely surprised when one of my theories turns out to be built on something more substantial than papier mache and dreams tbh.

The next step in this Patchface/Raven investigation is the one that will require a little effort. Basically we need to go through Clash, Storm and Dance (no Patchface in Thrones or Feast right?) and pull every interaction between Patchface and ravens. I can't imagine there are too many but there must be something with Mormont's raven at CB and perhaps that something will shed more light on who (if anybody) Patchface is communicating with. I added the parenthesis because it could be that Patchface is not directly communicating, he may in fact, just be mental. It could be though that due to his (effective) return from the dead that Patchface can perceive a presence of some kind in the raven and is just happy with himself and raving. It could also be that he is trying to communicate but he doesn't know who he is trying to communicate with. In other words, his mind was broken by his experience but it gave him perception beyond the normal, he can see Mel for what she truly is and he can see the raven for what it truly is and because he senses something bad gathering around Shireen (his friend) he is trying to fight his madness in order to warn someone, anyone what is coming.

Skinchangers are rare in Westeros for sure but it's not like they're dragons or mermen. The idea that maesters wouldn't know exactly what they are, how they work and how useful they would be is preposterous. Walgrave is being kept around because he can provide the maesters intel that they could otherwise not obtain.