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How do you find the key signature of a piece?
Here are some tips and tricks to help you decide what key a piece is in. A couple of things to memorize, then simply follow the steps outlined below!
When you learn music theory there are two situations that may be troubling when working out the tonality of a piece.
You want to know what key a piece is in, or have to answer a question about it.
1. That C major / A minor have no sharps or flats in the key signature
2. That F major/ D minor has only one flat.
3. And that the relative minor key is found a small 3rd (=3 semitones) below the major key.
Here are the tricks to finding what the key is:
First of all, you have to practice writing the order of sharps and flats.
Do it now! And learn it so well you could do it in your sleep! ; )
As you write, keep the sharps and flats neat and organized and not too far apart, neither so close that they touch.
So, when you are asked; "Write the key of D major." How do you know what to write?
The keys belong to either the Sharp "family" or the Flat "family".
First determine to which group it belongs. (This is easy and quick to do).
Major Keys using Sharps(#):
The major keys that use sharps(#) in the signature either
G D A E B F# C#
Major Keys using Flats(b):
The major keys that use flats (b) in the signature all have a flat(b) in the name, except from F.
F Bb Eb Ab Db Gb Cb.
Just start adding the sharps (or flats). For each added, remember the rules from above:
You were asked to write D major. So, since D is a basic (natural) note it belongs to the sharp "family".
First sharp added. A semitone higher is G. Ok, we're not there yet..
Second sharp added. A semitone higher is D. Yep! That's our key signature!
So, what if it is minor? Let's say you are asked to write the key signature for F# minor.
You have already memorized that the relative minor is found a small 3rd below the major key. Right?
First you need to find the relative MAJOR key. Which then obviously is a small 3rd UP from F#. This is A.
Then you simply follow the steps above to write the key signature for A major, which also is for F# minor.
Here is a link to a nifty online quiz to test your skills in minor keys!
Here are some examples to practice on.
In the first examples I'll guide you step by step. In the other, you should do the steps on your own, hover on the pictures for the answers.
Answer: D major or B minor.
Answer: Db major or Bb minor