(We do not teach tuning A4 with the tuning fork anymore. The fork is too sensitive to temperature and sometimes we need to set A4 above or below 440Hz precisely.
We now teach tuning A4 using an Electronic Tuning Device (ETD) and Double String Unison (DSU)
See this LESSON and this EXERCISE )
We usually use a tuning fork or an electronic sound source.
(From now on, I will always use the fork as the A440 reference,
but you could also use an electronic source.)
Listening to A4 and the fork together is one way to tune A4 to the fork.
The A4 above is out of tune with the fork.
You should hear a beat which indicates it is out of tune.
If you had trouble, listen to them again, but this time,
the A4 will be filtered so that you will only hear the beat
and not all the other partials present in the sound.
Now, play the [A4 and Fork] and then [A4Fork Filtered]
You need to be able to hear the sound of [A4Fork Filtered] within [A4 and Fork]
Aural piano tuners work to develop their ear's ability to filter out unwanted frequencies
so they can clearly hear the beats produced by out of tune intervals.
For example, listen to this recording of the same out of tune A4 and the fork,
but this time, the waveform will be filtered around E6;
the third partial of the fork and A4.
Play [A4Fork 3rd Partial] and [A4Fork].
Hear the beating 3rd partial within the [A4Fork] sound.
Next lesson - Try Tuning A4 to the Fork Yourself