How to find the correct key of any piece of music you hear

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How to find the correct key of any piece of music you hear

Postby PeterA » 22 Nov 2017 12:25

Clearly, I am referring to music that you hear and want to find the Key that it is written in, as opposed to printed sheet music, where it is obvious.

I assume that if you are reading this, you are not tone deaf, or you wouldn’t be a member of TDP.
So when you listen to a piece of music, try to sing or hum the note of the Key.
You can do this by listening to the piece, recognize certain resolution points, especially where the music seems to take a rest point, and particularly including the last bar and try to sing the correct note. It is actually easier than it sounds.

To find the name of the Key note, that you are still humming, sit at your keyboard, keep on humming that note and play notes starting at middle C and continue playing subsequent notes, going up in semi-tones until the note matches. This may be the Key note that you are after.
N.B. DVD’s and CD’s are generally in tune with your keyboard (unless you have changed the tuning – yes you can vary this on some instruments.) Tapes, like VHS and cassettes, can vary as the tape sometimes stretches and this can alter the pitch.

If you let the piece of music play right through, and you persistently strike the note you have chosen it will not sound out of place. Try it, with a piece you know. Any other note will jar at some point, or many points and you will know that you are wrong.
In which case you will have to start all over again. Most of the time you will hit on a good note, but that may or may not be the Key note.

If it seems to fit perfectly it may still not be the correct key. The reason is that the Key note, its third and its fifth will all sound good!
That is because these actual notes feature extensively in any piece of music, though they are not necessarily always in the melody line.

So how can we be sure which is the right key note?
What if I have stumbled on the third or the fifth and think that is the Key note?

Here is a simple trick that is easy to perform. Let us call it the minor chord trick.

Play a minor chord, in the root position that puts your chosen Key note as the one on top.

For example, if you think it is in the Key of C, and you want to check it out, then you will choose to play an Fminor chord because the note C will be the top note, when Fmin is played in its root position. (i.e. The C is the 5th of the chord Fmin).

Then, try each of the other 2 notes, one at a time of course, and see if one of these fits.
At least, one of them will definitely jar, or maybe both. In this example either the Ab or the F may sound better, or much worse.

If either sounds much worse, then C is the correct Key.
If either one sounds better
, and only one of them will, then that one is the correct Key note.

Why does this work?
If you have correctly chosen C as the Key, by persistently playing that one note of C throughout the playing of your piece, it will gel and may confirm your selection, subject to eliminating F or Ab as made clear below.

If you have chosen C as the Third, then the Ab will sound better, because C is the third of the key Ab. (If it jars, then the Key may be C or F).

If Ab sounds good, then the Key is Ab.

If you have chosen C as the Fifth, then if you play F, it will gel, because C is the fifth of Key F. So the piece is written in the Key of F.

This minor chord trick works for all situations.

To give another example, if you think the Key is F, for the piece you are listening to, you need to check it against Bb minor, in the root position. (i.e. F is in the top (5th) position.) So check your piece against the notes Bb and Db, which make up the chord of Bbmin, together with C.

If you are smart, you will use the Circle of Fifths (because you have memorised it) to instantly find the right minor chord to play. See how valuable this simple diagram can be!

N.B. The minor chord you need to play is a fifth below what you think the Key note is.

It is that simple.

To view an interactive version of the Circle of Fifths, click this link:

Do a right-click to open it in a New Tab

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Re: How to find the correct key of any piece of music you he

Postby Hugh-AR » 22 Nov 2017 23:08


That's a novel idea! I can see how that would work. It's humming that last note that may be a problem, but I'm sure my dog will help me on that one!

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Re: How to find the correct key of any piece of music you he

Postby Brian007 » 23 Nov 2017 07:41

Hi Peter,

A very interesting approach and one I will certainly give a try

Brian007 :D :D
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