Pi (update 2)
To continue the analysis of Kate Bush's song π (Greek letter p) from the previous update, I took this photo yesterday. As you can see, it is a woodland location, and there is an ancient-looking and apparently mysterious ivy-covered object in the picture. The object is a set of stones that have been carefully placed by hand, so this isn't the sort of random ivy-covered object that you typically find in a wood.
The reason I think you should be interested in this photo is that I deduced the precise location of the artefact from the song π. I very carefully triangulated the position of the artefact with respect to some known positions, and it is located to within a metre of the position that I had deduced before I arrived to take the photo.
I believe that this is convincing evidence that Kate Bush has indeed encoded a secret message in her song π, and that the message contains a puzzle for us to solve. I don't have any idea what the ultimate goal of solving this puzzle is, but if anyone puts an imaginative puzzle before me then I'm sure to bite on it. From what I have discovered thus far the puzzle is encoded in a layered way, so you have to solve it in stages.
My only slight concern is that (an abbreviation of) some of the lines in the song reads as "His numbers run him in a great big circle". One could imagine digging down through the layers of the puzzle, only to arrive back where you started after having invested a lot of effort. Oh well, that is how most of my research ends up, back at the starting point but much wiser.
Whither π? In locating this artefact, I have "used up" only part of the structure that I have found in π, so there is more to solve in this puzzle.
If/when anyone else visits the artefact please be careful, because I noticed that despite taking care I left some traces of my visit. Fortunately, the wood is a living growing being so it will heal itself.
Update: I just had someone (away from this blog) cast doubt on my sanity, because I am making these observations on the information that is secretly embedded in π. Well, all I can say is that the data is there for everyone to analyse, so this is a completely open exercise. What I don't want to do is to reveal prematurely what I have discovered, and thus to spoil the puzzle. That is the reason for the photo (which establishes that I visited a particular location), and the anagram "Heavy-hearted, contrary warmth" in the previous posting (which also identifies a relevant location). These two items do not give the game away, and they are proof-in-retrospect that I solved a particular part of the puzzle.