## A proposal to simplify the notation of EDOs with bad fifths

Dave Keenan
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Joined: Tue Sep 01, 2015 2:59 pm
Location: Brisbane, Queensland, Australia
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### Re: A proposal to simplify the notation of EDOs with bad fifths

George Secor wrote:
Dave Keenan wrote:66 is 1:3:17 consistent. It is not 1:3:p consistent for any other prime p up to 19 (no higher primes were checked). So no useful JI-based notation is possible for it. But the following apotome-fraction notation is acceptable. Although is not valid as 2 degrees, it's close.
66: AF (same as 59)
I agree -- with one exception: according to my spreadsheet 143C is indeed valid as 2 degrees of 66-EDO!
It's good that we agree on the notation, but it's strange that our spreadsheets disagree on this.

I've attached below, the spreadsheet I built last week for this purpose. It shows on a chart, how the size of each symbol's comma varies, as a fraction of the apotome, as the size of the fifth changes.

EDOs are listed under their fifth-size to the nearest cent. A table below the chart tells you how many steps-per-apotome each EDO has. You can then calculate the midpoints between steps, as decimal fractions of the apotome, and determine which symbols fall within the capture zone for each step. e.g. For an EDO with 2 steps to the apotome, a symbol must fall between 0.25 and 0.75 apotomes in order to correspond to 1 step.
comma apotome fraction vs fifth size.xlsx
comma apotome fraction vs fifth size.gif (216.2 KiB) Viewed 382 times

Dave Keenan