Acoustic Lesson 08 - Key Signitures and Scale Basics

We all have cringed hearing someone singing “off key”. But what does being “in key” mean. The key identifies the chord, major or minor, which represents the focus of the music. This is what gives us the resolve at the end of a piece of music. Many beginner guitarists learn chord patterns but may not be aware of why these chord patterns exist. A common chord progression in the Key of G would be G, D, Em, C.

What dictates this chord progression is the key in which it is played. Take for example all of the notes from each of the four chords: G, B, D; D, F#, A; E, G, B; C, E, G. Other chords played in the key of G will remain in this pattern. For example Am: A, C, E. This is why when playing chord progressions we change some chords from major to minor. Rearranged and the repeats omitted they would read like this: G, A, B, C, D, E, F#, G. These notes are the G major scale. So with this it can be said that the key of G has one sharp, F#. All of the other notes are natural.  The pattern of the major scale starting on the 1 is whole step, whole step, half step, whole step, whole step, whole step, half step. Try and apply this to a key of your choice. Here is an example of the G major scale written out. Notice the F# in the key signature.

It will look and sounds like this on guitar.

 

In musical notation the key signature is used to mark the key of the piece of music. A series of sharp or flats are placed on the staff to show which notes should be lowered a half step or raised a half step in accordance with the key.  Key signatures can be found on the staff after the clef and before the time signature. These sharps and flats also have a particular order they appear in. For sharps the order is F#, C#, G#, D#, A#, E#, B#. Flats appear in the reverse order: BEADGCF. A key will two flats will have a Bb and an Eb; key of Bb. A key with three sharps will have an F#, C#, and G#; key of A. To identify the key from the key signature there are some shortcuts you can take. If the key has sharps, go to the last sharp and go up one half step. This will tell you the key. For example if the key signature has the four sharps the last sharp will be D#. A half step up from D# is E and therefore we are in the key of E.  For key signatures with flats go to the second to last flat to identify the key. For example if the key signature has four flats the second to last would be Eb, thus the key will be Eb as well.

Keys can also be minor. The relative minor is a minor third, or three half steps, down from the major, regardless of whether it is a "flat" or a "sharp" key signature. The relative minor to the key of C major would be Am. Therefore, A key signature with no sharps or flats can be C or Am.. A key signature with one sharp can be G or Em and so on and so forth. A good way to determine the key in this case is to see if what chord  the piece of music ends on The minor scale also be derived from this same concept. Starting on E then plugging in the notes from the G major scale give us a Em minor scale instead of the G major scale they would be if we started on G.

It will look and sounds like this on guitar. 

Knowing the key we are and its scale gives us more flexibility in understanding the chords and progression we use when playing any given piece of music. Understanding these basics will allow to progress in our guitar playing ability much quicker.

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