Greg's Music Theory Page
Click here to download the offline
zipped version of this content.
Guitarists, click here for
detailed tablature of scales
Click here for a list of all
of the major scales and their respective key signatures.
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
- A group of notes, (no note is repeated) in which melodies/leads
- Diatonic Scale
- A seven-note scale consisting of half-step and whole-step
intervals. See intervals subsection of the
- 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
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.
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
- 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)
A C D E G - A Minor Pentatonic
A C D Eb E G - A Blues pentatonic.
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
- 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
* 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
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
|| 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
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.
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
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.
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
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
* 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.