How to Know the Key of Sheet Music - Reading Key Signatures

A student asked me how you know what key of piece of music is in. The answer is: by the Key Signature.

The Key Signature is at the beginning of the piece of music on the staff where there will be between zero and five **sharps (#) or flats (b)**written next to the staff symbol.

# means raise the note by a half-step
b means lower the note by a half-step

The circle of fifths is a great tool for seeing and understanding key signatures. If you don’t have a circle of fifths, there’s a trick to telling the key by a the key signature.

The trick is:

For sharps: whatever note the last sharp is written on, the key is a half-step above that note. So just F is sharped = Key of G.
F and C are sharped = Key of D.
F,C, and G are sharped, Key of A.

For flats: if there is one flat it is the key of F, and for the rest of them the second to last flat symbol is on the note that the key signature represents.
So flats on B and E = Key of Bb.
Flats on B, E, and A = Key of Eb

Thoughts comments on key signatures and/or the circle of fifths?

3 Likes

Oh, yes, @Luke. I feel like I did before the math lesson and I’m looking for reasons to “skip”. :joy: In the end it’s no use to you and you have to go through… Without theory worse practice, I did it, with the help of my keyboard it went well. :slightly_smiling_face: Greetings from Astrid :woman_in_lotus_position:

3 Likes

Hi @Luke. I have a framed circle of fifths on the wall in my music room. It’s the most useful music tool I have by far. Once you learn the basics of how to use the CoF, it becomes indispensable. Finding key signatures is just one of the many uses of the CoF.

3 Likes

Don’t know why musicians have ‘circle of fifths’ charts when it is so easy to remember with the following sentence:
Funny Carol Gets Drunk And Eats Grasshoppers.

Hope this helps,

Robert :stuck_out_tongue_winking_eye:
London, Canada

1 Like

what about flats

1 Like

That’s so cool.

Hello @robertchartrand2104,
you don’t want to know what that means in German. :joy: Greetings from Astrid :woman_in_lotus_position:

1 Like

Hi @ingog

As Luke wrote at the end of his message:

For flats: if there is one flat it is the key of F, and for the rest of them the second to last flat symbol is on the note that the key signature represents.
So flats on B and E = Key of Bb.
Flats on B, E, and A = Key of Eb

If that is still not clear then let us know what it is that you don’t understand and someone will try again.

Regards,
– Slim

2 Likes

Thanks, got it.

2 Likes

You da man, @Slim!

2 Likes