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Greg's Music Theory Page
SCALES
Most musicians choose a scale to play a
lead/melody which is derived from the key (or implying
key(s) of the underlying chord progression(s). However, more progressive
styles of Jazz take exception to this method, deriving scales from the immediate
underlying chord or progression as opposed to keys. But in most other styles of
music, a lead/melody can be chosen based upon the key of the song or
progression. The subsequent text will focus on the first method. Using this
method as a building block, a musician can then, if desired, learn the more
progressive jazz method as well.
When you are ready to explore the second
method, I recommend Marc Sabatella's A Jazz Improvisation Primer".
See the keys section as an aid to this section.
SOME DEFINITIONS
- Scale
- A group of notes, (no note is
repeated) in which melodies/leads are derived.
- Diatonic Scale
- A seven-note scale consisting of
half-step and whole-step intervals. See intervals subsection of the
chords section.
- Pentatonic Scale
- Loosely defined as a five note scale,
the pentatonic usually refers to the specific 5 note scale derived from the
major and natural minor scales.
- Tonal
Center
- The note in which all of the chords
in a song or progression "revolve" around. This note will sound most "at
rest", yielding the least dissonance. The tonal center is usually the same
note as the major or minor key. When the key and the tonal center differ,
modes are used.
Using the circle of fifths to construct a
diatonic scale one can derive all of the scales needed to play leads/melodies.
To understand scales more in-depth, we
need a basic understanding of intervals, located within the
chords section.
Major Scale
A major scale consists of the following
intervals:
- Whole Whole Half Whole Whole Whole
half
A natural minor scale scale consists of
the same interval sequence with a different starting point.
- Whole Half Whole Whole Half Whole
Whole
Click
here
for a list of all of the major scales and their respective key signatures.
Relative Minors
Every major scale has a corresponding
relative minor scale. A relative minor is a minor scale consisting of the same
notes (key signature) as it's relative major.
For example; A minor is the
relative minor of C major. Compare:
- C D E F G A B - C major
- A B D E F G A - A minor
Another example; D major is the
relative major to B minor. Compare:
- D E F# G A B C# D - D major
- B C# D E F# G A B - B minor
Notice that in both examples, both scales
contain the same notes, and therefore share the same key signatures, but have
different starting points. In the last example, both the D major and B
minor scales have 2 #'s, C# and F# as their key signatures.
The 3 types of minor scales
There are 3 types of minor scales. The
harmonic minor, melodic minor, and natural minor.
- Natural minor
- The natural minor is the most common
scale, because it is simply the major scale starting on the 6th scale
degree. (B minor is the D major scale starting on the B, it's
6th scale degree.) Whenever you see a scale that is just labeled "minor"
without the "natural", "harmonic" or "melodic" labels preceeding it, it is
safe to assume that this is a natural minor scale.
- Harmonic minor
- The natural minor scale with a raised
7th scale degree. (A B C D E F G# A)
- Melodic minor
- The natural minor scale with a raised
6th and 7th scale degrees (A B C D E F# G# A)
The Pentatonic Scale
The Pentatonic Scale is a five note scale,
derived from the seven note diatonic scale. There is a major and minor
pentatonic scale. The major pentatonic, derived from the major diatonic scale,
is voiced 1, 2, 3, 5, 6. An example is C D E G A. The minor pentatonic, derived
from the minor diatonic scale, is voiced 1, 3, 4, 5, 7. An example is A C D E G.
The Pentatonic scale is very popular in rock and blues. It is also interesting
to note that this scale is also used in Eastern Asian music, especially in
Chinese music.
The Blues Scale
The "blues scale", or blues pentatonic is
just a minor pentatonic with an additional note (b5) making it a hexatonic (6
note) scale.
A C D E G - A Minor Pentatonic
A C D Eb E G - A Blues pentatonic.
Applying scales
This leads us to learning how to apply
scales to musical contexts. The traditional method is to simply find the
key signature of the
song/progression and play the corresponding scale. If the song/progression is in
the key of Bb major, the Bb major scale can be played over top of
the corresponding song/progression. Also, the Bb major pentatonic scale
can be used, since it is a derivative of Bb. In fact, any scale derived from the
Bb diatonic, would work, in the key of Bb.
Modes
- A mode is
- a scale, derived from either the
major, natural minor, harmonic minor or melodic minor scales, that is played
starting on a note different than the tonic.
- Another way of thinking about it is:
- a scale, derived from either the
major, natural minor, harmonic minor or melodic minor scales, that has a
tonic that is different from the key.
The following is a list of modes for the
C major scale:
- C D E F G A B - Ionian
- D E F G A B C - Dorian
- E F G A B C D - Phrygian
- F G A B C D E - Lydian
- G A B C D E F - Mixolydian
- A B C D E F G - Aeolian
- B C D E F G A - Locrian
You've already learned one mode, the
natural minor scale(aeolian). A minor is a mode of C major.
Learning the names of the modes is
perhaps, half the battle, but don't get hung up on them. They are only
beneficial to the student in so much as they provide a means of communication.
Their are three ways that I suggest to
learn modes. One, to become better acquainted with this subject, is simply to
play the modes as listed above.
The second way is to compare each of the
modes with it's major or minor counterpart.
Take a look at the modes once again. This
time I've added the major or minor label next to each mode. This indicates
whether or not the mode most most closely resembles the major or minor
scale.
- C D E F G A B - Ionian (Major)
- D E F G A B C - Dorian (Minor)
- E F G A B C D - Phrygian (Minor)
- F G A B C D E - Lydian (Major)
- G A B C D E F - Mixolydian (Major)
- A B C D E F G - Aeolian (Minor)
- B C D E F G A - Locrian (Minor)
Notice that the list of resembling scales
for these modes, aside from the locrian, matches the pattern found in the
number system.
* The locrian corresponds, in the
number system, with the diminished chord, but since a diminished chord is simply
a minor flat 5, we will think of it as a minor scale for simplicity's sake.
So the Ionian, Lydian, and Mixolydian
scales can be compared to their corresponding major scales with the same root,
and the Dorian, Phrygian, Aeolian and Locrian, scales can be compared to their
corresponding minor scales with the same root as follows:
| MODE |
CORRESPONDING SCALE
|
MODAL DIFFERENCE
|
| A Ionian |
A major |
Same scale |
| A Dorian |
A minor |
Minor w/#6 |
| A Phrygian |
A minor |
Minor w/b2 |
| A lydian |
A major |
Major w/#4 |
| A Mixolydian |
A major |
Major w/b5 |
| A Aeolian |
A minor |
Same scale |
| A Locrian |
A minor |
Minor w/b2 and b5 |
The third way to learn how modes sound is
to play them over their corresponding major, minor or diminished chord. If you
play just an F lydian mode, it will sound like a C major chord starting on F.
But, if you play this same mode over an underlying F major chord, the character
of the lydian mode will "jump out".
Because the modes are so close to their
major or minor scale counterparts, it is essential for the musician to emphasize
the note which distinguishes the mode from it's counterpart. For instance, since
C lydian is a C major scale with a sharp 4 (F#), it is important for the
musician to emphasize the F# when playing this scale. Otherwise, the listener is
more likely to hear a C major scale instead.
Applying modes
One way to apply a mode is within a "modal
chord progression". A modal chord progression (my contrived term) is a chord
progression within a song which deviates from the key of the song and allows for
a mode to be applied.
"Amazing Grace" has the following chords
in it.>
G major, G major, C major, G major, G
major, A major, D major
This song, in the key of G major has one
chord which deviates from the key. A major. The A major (A C# E) chord is
functioning as a II chord. II's chords are minors within major keys. The C# is
not within the key of G. G has only one sharp, F#. A G major scale would work
for this whole song, even over the A major if one does not linger on the the C
note of the scale, thus yielding dissonance.
But, another option, is when the A major
chord is encountered, the G lydian mode can be used. The G lydian is the D major
scale starting on it's 4th scale degree (G). Why call this scale a G lydian
instead of just D major? Because the tonal center
of the progression is G.
Another way of looking at this progression
is to think of the A as temporarily modulating the song to the key of D major.
Either way, you get the same results, but it's easier for most people to think
modally.
Using Pentatonic Scales Over Modal Chord
Progressions
Even though I said that in Amazing Grace,
the major or ionian scales can be used over the song's chord
progressions, the actual melody of the song is derived exclusively from the
major pentatonic scale.
The pentatonic scale holds a unique place
among modal chord progressions because all of its missing notes (major
pentatonic = major scale minus the 4th and 7th scale degrees) are notes that
distinguish the major scale from major modes and minor scale from minor modes
(comparing minor pentatonic to minor modes).
So if you're playing a lead over top of a
song that has a modal chord progression and you know the song has a major or
minor tonality, one option you have is not to worry about what mode(s) the
song's chord progressions are following and simply play the corresponding
pentatonic scale. This is especially useful when the song is shifting modes.
Joe Satriani uses a technique that he
calls "Pitch Axis Theory" to compose a song using one tonal center, cycling
through multiple modes in the same song. So a song may be in the key of E, but
have chord progressions and melodies that cycle through E ionian (major), E
lydian and E mixolydian.
Now while he uses this primarily as a lead
technique, let's say you're jamming with Satch and he asks you to take a solo.
Instead of you having to know all of these modal changes, you could simply play
E major pentatonic over the entire lead. Now granted, Satriani usually goes one
step further and will use parallelism also, meaning that he switches tonalities
from major to minor so you might need to jump from say, E major pentatonic to E
minor pentatonic, but the point is that the major pentatonic scale will work
over ionian, lydian and mixolydian chord progressions, while the minor
pentatonic scale will work over dorian, phyrgian, and aeolian chord
progressions.
Composing music using modes
The subject of modal chord progressions
leads us to an important point in regards to composing music using modes. Just
as we noted earlier that it is necessary to emphasize the note(s) that
distinguishes a mode from it's major or minor counterpart, so it is equally
important to emphasize the chord that distinguishes a modal chord progression
from it's major or minor counterpart.
Keeping in mind the pattern mentioned in
the Number System section, where I IV and V are major,
ii, iii and vi are minor, and vii is diminished within a major key, if we were
to play or write a song that utilized a mixolydian chord progression, the
numbers would be I IV and bVII are major, ii v and vi are minor, iii is
diminished. Here are the chords of C mixolydian as an example:
- I - C E G - C Major
- ii - D F A - D Minor
- iii - E G Bb - E diminished
- IV - F A C - F Major
- v - G Bb D - G Minor
- vi - A C E - A Minor
- VII - Bb D F - Bb Major
If you merely played the I, ii, and IV and
vi chords in this song, there would be no distinction between this being a
mixolydian chord progression as opposed to a standard major chord progression.
Therefore the differences need to be emphasized. The differences between a major
progression and a mixolydian progression are the ii diminished, v minor and the
VII major. I've gotten to a point now that whenever I see these chords in what
appears to be a major chord progression, I automatically associate it with
mixolydian.
For a lydian progression, the II major,
the #IV diminished, vii minor chords distinguish it from a major (Ionian)
progression. All the modes have certain chords that need to be emphasized to
distinguish them from a major or minor scale. Find those chords and exploit
them.
Scale and lead ideas
Here are some general ideas to develop
your lead playing.
There are 3 basic elements to playing
lead.
They are:
- Scales
- Arpeggios
- Intervals
1. Scales
Learn to play these in sequences/patterns.
Take the notes out of their straight order. I tend to number the notes of
scales, numbering the tonic as 1, etc. I then will play scales according to
numbered patterns. For instance, if I'm working with the F major scale, F is 1,
G is 2, etc.
Here are some examples of numbered
patterns
- 1 2 3 4, 2 3 4 5, 3 4 5 6, 4 5 6 7
- 1 3 2 4 3 5 4 6 5 7 6 1
- 1 2 3, 2 3 4, 3 4 5, 4 5 6, 5 6 7
- 1 2 3 4, 3 4 5 6, 2 3 4 5, 4 5 6 7
These are just for starters. I'm sure you
can come up with more on your own.
And finally, you may want to experiment
with scales that contain notes which are "outside" of the key of the underlying
song/progression. "Playing outside" can add some color to an otherwise dull
melody/lead. The blues scale is a scale which contains one note which is
"outside" of the minor key. Don't limit the blues scale to minor keys. Even
though it's is based upon the minor pentatonic, it also works great when played
over songs in major keys, giving them a blues feel.
2. Arpeggios
Arpeggios are simply broken up chords. For
instance, by playing the notes of the D major chord, D F# A, one is playing the
D major arpeggio. Arpeggios can be chosen based upon the key of the
song/progression or the immediate underlying chord. One exciting way to use
arpeggios is to choose one which enlarges a chord. For instance, playing the b
diminished arpeggio over a G major chord, produces the sound of the G dominant 7
chord, even though neither the chord or the arpeggio *alone* is playing G 7.
Arpeggios do become more like scales if they are derived from chords which are
bigger than 4 notes. This is because chords beyond 4 notes tend to transcend
octaves. My favorite arpeggio is the Minor 7 arpeggio, because it is so close to
the famous pentatonic scale. Compare:
- A C D E G - A minor pentatonic
- A C E G - A minor 7
3. Intervals
* See the Intervals subsection of the
Chords section for more
detailed information.
Intervals can be played two ways. They can
be played together, like a chord, or separate, like an arpeggio. Intervals can
break up the monotony of scales and bring a "freshness" to any, otherwise
predictable lead. One easy way to find some appropriate intervals for a song is
to derive them from the key of the song/progression. Of course, one can also
play intervals which aren't in the key.
I
love the guitarist, Eric Johnson's approach to intervals. He plays them by
skipping strings, and playing them in groups of three. One interval that he
plays a lot is voiced, 1, 5 9. This is the outline of a ninth chord and works
well over major or minor chords.
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