home > music theory > key signatures

Music Theory:
Understanding Key Signatures

When musicians talk of scales, or even a piece of music as being in a certain key; i.e., this song is in the key of, F Major... they are defining the key signature and tonality off of the tonic note, (the, tonic, is the key note of a scale), and the specific notes (and to a lesser extent the chords), found within the piece. The altered tones found in the scale are the signature, the tonality is the key's center, (or Key Center).

For example:
If we say a certain melody is in the key of
G Major, then the melody is made up
of notes from the, G Major, scale;
G, A, B, C, D, E, F#.

The tonic note, (or first note - key note), of the scale is; G, but the key center is G Major.

Key signatures are given at the beginning of a piece of music. They are shown as the appropriate sharps or flats on the staff for the prescribed key. The sharps and flats are indicated between the clef and time signature. When placed on the staff in this manner we call this the, Key Signature.

Key Signature example:


Join the Members Area

The key signature example shows us the scale tones used in the piece must employ use of F# notes with all other notes natural. It does not however indicate whether the key center is Major or Minor. We must look to the music and chords for the Key Center information.

One of the first things you will notice is how the order of the accidentals, (sharps & flats), follows a recurring pattern. We begin the design of musical keys with the C major scale.

The key of C major is neutral and has no sharps or flats. If you look at the example you will see G major is the first sharp key. It contains one sharp. The first flat key is F major.

It contains one flat. The keys follow a pattern, as you travel to the next key you add on a new accidental, but keep the previous one(s) from the last key. The common agreement between keys allows us to come up with a simple and useful system of memorizing the
accidentals through all of the keys.


For more information download the handout available for this lesson...

Download the PDF Handout:

(6 Pages - Includes all explanations, Key Signatures and Written Assignments)

Key Signatures - PDF Handout