The Ribbon Device

What are key signatures? A key signature is a group of either sharps (#) or flats (b) that sit between the treble or bass clef & the time signature at the start of a piece of music. The number of sharps or flats tells you what key the piece of music is in. For example if the key signature has 3 sharps the song will either be in A major or F# minor. Ok so now thats out of the way lets understand why you want to know this stuff. Say you want to work out a piece of music by ear then you will need to have some boundaries. In music we only have 12 different notes (on a piano thats 7 white notes & 5 black notes), this is our widest boundary. Now in most songs we don't use all 12 notes, that would be like making a sandwich with the entire contents of the fridge. Instead we commonly use a selection of 7 notes out of the 12, which we call scales. (There are many different scales out there but to understand key signatures we are going to keep to the basic major scale.)                                       

To give you a visual of this here are all 12 notes or our widest boundary:
| 1  | b2  | 2  | b3 | 3  | 4 | #4 | 5  | b6  | 6 | b7  | 7  | 1 |
| C | Db | D | Eb | E | F | F# | G | Ab | A | Bb | B | C |

And here is 7 of the 12 notes or the "C major scale" or we can also call this the key of "C major".

| 1  |   | 2  |   | 3  | 4 |   | 5  |    | 6 |    | 7  | 1 |
| C |   | D |   | E  | F |   | G |    | A |    | B | C |

As you can see that the Key of C major has no sharps or flats in the scale. And in example 1 below you can see there are no sharps or flats in between the treble clef & the time signature. Therefore this song is in the key of C major.



Here is the "G major scale" or we can also call this the key of "G major".
| 1  |   | 2  |   | 3  | 4 |   | 5  |    | 6 |    | 7  | 1 |
| G |   | A |   | B  | C |   | D |    | E |   | F#| G |



As you can see that the Key of G major has 1 sharp in the scale. So in the example below you can see 1 sharp in between the treble or bass clef & the time signature.

The way I like to understand the word "key signature" is by thinking of these words separately.
We use a "key" to unlock something and a "signature" is a proof of identity.

Next week I will talk more about the similarities between different key signatures.

cheers
Mat