Unit 16 Demonstration

Using the Top Octave Test

M3 = M10 < M6 = M17
1. Tune the top note as a clean DSU.
2. Check the bottom 4:2 octave (M3 = M10).
3. Confirm the M6 is a little faster.
4. Tune top note so M6 = M17.
5. Check the top 4:2 octave, M3 = M10.
In this example the P12 sounded pure but when I checked the tests, they were not equal. This can happen due to coupling. Coupling can happen when the coincident partials are not equal but they become equal when the interval is played. But if the P12 coupling causes a partial to change, it can return to its original frequency when played in the top octave. Fixing the top octave may make the it cleaner but the P12 remains unchanged; the P12 is still pure. There's just less coupling needed and occurring.

I also run through the regression tests for each interval note even though they are not needed.