When a string is played, it vibrates in different modes. It can vibrate in one section, two sections, three sections, etc.
These modes are called partials or harmonics.
The following graphic shows how the harmonics relate above the note A4.
When two or more strings are tuned together, all of their partials must have the same frequency or beating will be heard.
Listen to the beating of the 6th partial on this out of tune Bb3:
Analysis of a Bb3 Before and After Tuning.
A Bb3 on a Kawai GX-2 grand was measured before and after tuning.
Measurements were done by filering each partial and looking for volume fluctuations or beats. (A clean unison has no beats on any partials)
A mark was given out of 4 for each partial.
PARTIAL | Waveform Before | Audio Before | Waveform After | Audio After |
|---|---|---|---|---|
Unfiltered |  |  | ||
1 |  |  | ||
2 |  |  | ||
3 |  |  | ||
4 |  |  | ||
5 |  |  | ||
6 |  |  |
