[floatingatoll]

This reminded me of a spiral/helix of fifths music theory poster I had twenty years ago. I can't find it now, but in my research, this came up:

Music Through Computation, Carl McTague, 2003 International Mathematica Symposium https://www.mctague.org/carl/music/computer/talks/music-talk...

And it does indeed have a nice picture for "Helix of Fifths" that is a dry black and white sketch of what was on that poster.

[telesilla]

Ouch my poor brain went into shock reading that! I'd done all I could to forget schenkerian analysis and now it's all flooding back. Aside from that, nice intro to helical harmony.

[floatingatoll]

I'm sorry / cheers :)