We will now advance one step closer to modulation. By now you should be up on the pentatonic scale in every position. It is vital to know this scale in every position and in as many different keys as possible. Of course this all takes time to accomplish, but to be in total control of your instrument you must understand it.
You should also be up on the major scale and itís relative minor. To understand modulation, you must become familiar with all the major diatonic scales and the chords within each scale. Once you understand the diatonic major scales and each relative minor scale, we will advance onto other scales (harmonic and melodic) and modulation.
Before we move on to modulation, we must understand the functions of each chord in the diatonic scale. We will continue to work with the key of C major and its relative minor or Aeolian scale Am.
The notes and chords in the key of C major are C, Dm, Em, F, G, Am and B diminished. In our earlier lessons I touched on cadence. In that lesson each note in the key of C major was given a name.
The first note in each key is the home note and is also referred to as the tonic or final. The second note is called the Super tonic. You will find each note and the name illustrated below, all the notes in the key of C major and the names that will be associated with them.
I C Tonic The first note in the key, referred to as the home note or final.
ii Dm Supertonic
iii Em Mediant
IV F Subdominant
vi Am sub Mediant
vii B diminished Leading tone
If you are playing in the key of C major and strum the C chord (I), it is said to be at rest or inactive. In other words when this chord is played it does not demand resolution. Notice the notes of the C chord below. The notes that make up the C chord are C, E and G. Notice that none of those notes have an arrow pointing to another note. Now notice the D, F, A and B notes below, each of these notes have an arrow pointing to another note. For example the D note is pointing to the C note, the F note is pointing to the E note, the A to G and B to C. This means that the notes with the arrows are active notes and want to resolve to the notes they are pointing to.
If you strum the G chord, which is the (V Dominant)
chord in C major, the G chord wants to resolve to the C chord. There are a number of reasons why the G chord wants to do
this. The notes that make up the G chord are G B and D. The illustration above shows the G note is at rest or inactive.
But the B note wants to resolve to the C note as the arrow indicates. The D note also wants to resolve
to the C note.
So the Dominant chord in any key wants to resolve to the tonic note or home note. Strum the C chord then the G chord; notice that the G chord wants to return to the C chord. This is called an authentic cadence. An authentic cadence is established when the penult (V) chord and the final (I or i) chord are played in order.
What does this mean? Strum the C chord and then G
chord and then the C chord; you have just played an authentic cadence. Recall our inversion lesson, in that lesson you played each chord in a different inversion. You played the C chord out of the root position or with
the E and G in the higher position over the C note.
If you play the authentic cadence with the tonic
chord in its root position you have played what is called a perfect cadence. In the key of C major you have played the C
chord in the root position and highest note. The perfect cadence is also an authentic cadence.
If you play the same two chords, G and C, but
invert the tonic or C chord, you have played what is called the imperfect cadence. An imperfect cadence is also
authentic, but the tonic chord is not played in the root position. It has been inverted. When you invert the tonic
chord, you weaken its final function. When the tonic is played in its root position, you will have a much stronger final
or decisive ending.
Then we have the Plagal cadence. This is the I IV or the i iv cadence. In the key of C major the IV chord is the F chord. There are times when you want a different sound and you can achieve this by using the ii chord or Dm instead of the F chord. The Dm is the relative minor to F major and can be substituted. I donít want to make this to difficult so we will talk more about this substitution stuff later on down the road.
I-ii or C to Dm
So we can play, C, G and C for the authentic
cadence and the C F C for the Plagal cadence. We can now even put these both together to get the famous, I, IV, V
progression. In the key of C major this progression would be C, F and G. Or, C, Dm, G and then C. This would be an I-ii,
V, I progression.
There is also a cadence called the interrupted cadence. When the V chord resolves to any other chord then the tonic (I or i) it has been interrupted. Your ear knows something unusual has happened.
We get the deceptive cadence when the V chord
resolves to the vi chord. The vi chord can also serve as the tonic. The ear is fooled but accepts the change. Look at
the example below. I, IV, V, I, ii, V, vi.
C, F, G, C, Dm G, Am
The half cadence is not complete, the chord
progression stops on the V, paused.
By knowing how the different types of cadence work,
we can begin to figure out how songs are written and write our own.
The examples given above have been illustrated in
the key of C major. What happens if we use this same technique described above, but use the Am scale? Recall that the
relative minor is always the sixth note in the major key. Am would be the relative or nature minor in the key of C
major. If we wanted to write our song in Am, we would write out the notes like illustrated below.
Am, B dim, C, Dm, Em, F and G. Notice that the (A
i) is now the first note. Am is now the first chord and will represent the tonic chord. Both C and Am can function as
the tonic. We can now use the (i iv v) progression. Am, Dm, Em. This progression will not be as decisive as the major
progression (I, IV, V) C, F and G. The Aeolian minor progressions give the sadder sound but also have the weaker
cadence. The major progressions give you the happier sound.
For now we will concentrate on the minor
progressions developed in the Aeolian or Am scale. Recall from the earlier lessons that each chord can be given a
numeral. The chords of the Am scale can be written out as follows. Am, B dim, C, Dm, Em, F and G. Written out using
the roman numerals you would have (i, ii, bIII, iv, v, bVI, bVII)
So if we wanted to write a (i, iv, v progression)
we would play Am, Dm and Em. In the key of C major we learned that we could substitute the F with the Dm, we can do the
opposite when in the minor scale. This means we can now play the F chord instead of the Dm chord. We can also use the G
chord instead of the Em chord. This would give us the (i, bVI and bVII) progression. This would be (Am, F and G)
Listen to the Am, F and G
picking on the acoustic. Learn it here.
The notes for the minor scale would look like, 1,
2,b3, 4, 5, b6, b7 or A, B, C, D, E, F, G
Strengthening the Aeolian Cadence
There are number of things that can be done to the
natural minor scale to strengthen its somewhat weak cadence. One thing to do is to convert the (Em or v) chord into a
major chord. If you change this chord into a Dominant chord, it will make the cadence much more decisive and bring
closure. One way to convert the Em into the E major chord would be to raise the 7th note of the Aeolian
scale by one half step. This would change the G note to G#. The notes that make up the Em chord are E, G and B. The E
chord has the following notes. E, G# and B. By raising the G note to G# will convert the Em to E major. But it will also
do something else. It has now changed the G chord into the G# Diminished or G#m b5 chord. It also changed the C chord
into the C Augmented.
The new chords would be, Am, B diminished, C augmented, Dm, E, F, and G# dim.
So now we have the Harmonic minor scale. The harmonic minor scale has the following notes and chords.
Am, Bdim, Caug, Dm, E, F and G#dim. Now we have a
major chord, (E) as the V chord. We can construct the following progression out of the Harmonic minor scale.
Am, Dm and E. Strum
those 3 chords and notice how it resolves onto the Am. It gives a very definite closure. Notice that it has a more
powerful cadence over the Am, Dm, and Em chords of the natural minor scale. Also notice the large interval between the
bVI and Diminished vii of the harmonic minor scale. This large gap can make the harmonic minor scale a bit awkward in
improvising, but the strong cadence is the much-desired effect.
To offset this large melodic interval, we can use
the melodic minor scale. The melodic minor scale has the notes that follow.
A, B, C, D, E, F# and G#. We would raise the 6th
and 7th note of the Aeolian minor to get the melodic minor. By raising these two notes we now have a couple
different chords to contend with. The chords of the A melodic minor scale are now. Am, Bm, C aug, D, E, F# dim and G#
So now we have looked at the Aeolian or natural
minor, the harmonic and melodic minor scales. We looked at couple different ways to work on the cadence and construct
the progressions. Itís up to you to work on the scales of each.
We can use the Major scale and the minor scale to construct our songs. We can use the harmonic minor to strengthen the weak Aeolian cadence and the melodic minor to smooth out the large interval of the harmonic minor scale. Once we do all of this we can have some real interesting music going on. Before we put all of this together, we need to learn more about the major scales, common chords and parallel keys. Stay tuned.
Use the blank forms
to fill in the A Harmonic and A melodic minor scales.
Practice the Harmonic minor and Melodic minor
Write out an I, IV, V progression in each scale, major, minor, harmonic and melodic minors.
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