I am reading through Robert Bringhurst's Elements of Typographic Style (4th edition) once again and especially Chapter 8: "Shaping the Page." My publication is a multi-column periodical; page size is standard 8.5x11" or close to it. I'm trying to use his chromatic scale (page 146) to determine the proportions of the text block. Most of the graphic design forums I appeal to for help just give me a blank look, so I turn to typographers.
My question: If you have a given page size (let's say 8.5x11," which corresponds to the tall half-octagon or a fourth on the chromatic scale), how do you determine the text block? Just mix and match it with the other proportions (major 6th, diminished 5th, major 3rd, etc.)?