**NAME:**Spreadsheet for calculating chord frequencies

**BASIC CONCEPT:**

Recently I was retuning a chord harmonica. I found myself getting a little mixed up with "cents". I understand why musicians use them, but the physicist in me just wants to calculate absolute frequencies and be done with it.

What I present below is

**A DRAFT. I DON'T KNOW IF IT IS CORRECT. I ask for construcvtive input from the experts.**

Note that if I got this basically correct, values other than 443 can be substituted. Users can customize this spreadsheet easily.

**WHEN/HOW:**February of 2018.

**LAYOUT/DETAILS:**

There are several schools of thought around "just" intonation.

In pretty much all styles of "just", the ratio between the root and perfect fifth is 2:3. This happens to be within 2 cents of where the fifth falls in equal temperament (ET). This makes for an extremely smooth dyad. The only dyad smoother than this would be an octave (ratio 1:2).

In pretty much all styles of "just", the ratio between the root and major third is 4:5. This is about 14 cents flatter than where the major third falls in ET.

When it comes to sevenths, there are several schools of thought. I will here focus on

**.**

*three different ways to define the minor seventh*