Constructing Major Scales

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[ Constructing Scales ]  [ Key signature theory ]

Constructing major guitar scales and guitar chords in the major key

All major guitar scales are built the same way with the following steps. Whole, whole, half, whole, whole whole half steps. A whole step consists of 2 frets on the guitar and a half step consists of 1 fret.

Major guitar scale contruction

Notice that there are 3 major chords, 3 minor chords and 1 diminished. If you were to play in the key of D Major as illustrated above, it would now be D Ionian. If you were playing in the key of C major, it would be C Ionian.

All major keys are constructed the same way as illustrated and once constructed, there will always be 3 major, 3 minor and 1 diminished chord for that major key.

Major scales and scale construction

If you’re not familiar with reading music, here’s a real basic idea of what’s going on. Notes can continue above and below each of the lines. The key of C does this and has been illustrated below.

Reading music

Major scale and chords

Look at the illustrations above illustrating the key of C major. A good way to look at music is how it is so mathematical and how it all repeats. 

I explain the key of C major for a very important reason. Once you understand the construction of C major, building other major keys and their scales are similar. Once you learn the modes in the key of C major, they repeat the same fingering patterns in other keys. One more thing, the key of C has no sharps or flats to work around. Also called accidentals.


There are tons of other scales to learn, the harmonic minor, melodic, diminished and so on. But you can construct other scales using the illustration above.

The illustration below, will begin to explain how the chords are formed for any given key.

The illustration above shows the notes of C major scale. Each note above can be given a number 1 through eight. There are 7 different notes to every major key. In the key of C, they would be:
C, D, E, F, G, A, B and then C repeated one octave above the first. Notice how there are no sharps or flats in the key of C major. No accidentals. 

The first note above is the C note and we will now construct the C chord. Remember every major scale is made up of in order, Major, minor, minor, Major, Major, minor and diminished chords. So the first note above is the C note the first chord in any key is always a Major chord. So we need to build the C Major chord. Look at the illustration below. This illustration now shows the notes numbered 1 to 7. The numbers now represent scale degrees. The Major triad or three note chord is always constructed as illustrated below. That being, the (Root 1), 3rd and 5th. Notice those notes below, C, E and G. All Diatonic chords within a key are built upwards in 3rds. Major chords, 1, 3 and 5.

C guitar chord and notes.

If we wanted to construct the Cma7 chord, we would add the B note. Each note being upwards of a 3rd apart. 1 being the first note and counting up 3.
Cma7 = C E G and B

C major 7 chord and the c major scale

The illustration below now shows the chords and the notes of each chord. We are still in the key of C major.

Chords of C major

The illustration below now shows how to construct the minor chord. We will show how to form the Cm chord. The minor chord is constructed using the 1st root, flat 3rd and 5th. Look at the illustration below and notice that the 3 note now is flat. It is still formed in 3rds, but the 3rd is flat in all minor chords. The 3rd note E has been lowered one half step or 1 fret. All minor chords are constructed with the 1st flat 3rd and 5th notes.

Notes of C minor chord

The illustration below will show how the C Diminished chord is formed. The diminished chord scale degree consists of the 1st root, flat 3rd and flat 5th. Quick note, the C Diminished chord can be considered the Cm flat five. 

In the key of C major the B dim is also the Bm flat 5. To make things even more confusing, it is at times referred to the half diminished.

Notes of the Diminshed chord

The illustration below shows how to form the C Augmented chord. 1st 3rd, sharp 5th.

Notes of the Augmented chord

When we improvise in the key of C major, we have the chords, C, Dm, Em, F, G, Am, B dim.

The trick behind playing lead is to know what chords are in what key. Or at the least know the relative minor to each major key. For instance, the Am is relative to C in the key of C. Why?, because they share the same signature, no sharps or flats. The relative minor is always the sixth note of that particular key. Look above and see that the A note is indeed the sixth note. The sixth note is also the Aeolian mode in every key. The sixth note also represents the minor chord. So the A above is the Am chord in the key of C. 

So in the key of G, the E would be the relative minor. G, A, B, C, D, E, F# . E is the 6th note in the key of G major. E is also a minor chord. E also represents the Aeolian mode in the key of G major. I believe a good way to switch keys, is to know the Ionian and Aeolian for each key. This is NOT the complete answer, but it is a good starting point. Why switch keys? Because certain notes sound better together than others. For example if you where playing in the key of C major and the G came up, you could switch to the key of G major. Why? Because the key of C has the F note. The key of G major has the F# note. I prefer the F# in the key of G major. The only difference between the key of G and C is the F and F# notes. C has the F and G has the F#. So I would base the lead on the E Aeolian and G Ionian for the Em or G chords. F# is also the leading tone for the G. Lead into the G with the F and then lead into the G with the F# and notice what it sounds like. We will learn more about switching keys and playing over changes later down the road.

Real quickly in the key of C major the chords can be classified.  The C I, Em iii, and Am vi produce the tonic sound. The Dm ii and the F IV produce the sub-dominant sound. The G V, and Bm (flat 5) VII are the Dominant chords. Play the Bm flat 5 or G7 and see how it wants to resolve back to the C chord. We will touch more on this subject in the future.

In the next lesson you will use the formula above to write out a few major keys. C, G, D, and A. Figure out the relative minor for each of these major keys. Consider the Ionian and the Aeolian the same for each key, but know the difference. The difference being in the key of G major, the G Ionian or G major, is G to G and E Aeolian Em is E to E. But each of these modes share the same signature, so you can play these modes over Em and G chords or any of the chords in G major.

Good luck,

Guitar Secrets