MUSI 491-001
FRETBOARD HARMONY
Instructor: Felipe Vargas Magdaleno
E-Mail: vargaslf@uwec.edu
Phone: 715-836-3633
Haas Fine Arts Center 149
Lesson 02 – Diatonic Scales and Tertian Chords
A diatonic scale is not a specific scale, but rather a way a scale is constructed. Diatonic
scales are constructed from a mix of whole steps (tones) and half steps (semitones).
A diatonic scale is any heptatonic scale that includes five whole steps and two half steps in
each octave, in which the two half steps are separated from each other by either two or
three whole steps, depending on their position in the scale. Examples of diatonic examples
are the Major scale, Natural Minor scale, and the Greek modes. In tonal music, the chords
for a specific key will derive mostly from diatonic scales and its alterations (Harmonic
Minor and Melodic Minor). In order to build the chords of a given key we must understand
how the scales are formed and its intervallic content.
The Major Scale
The major scale (or Ionian mode) is one of the most commonly used musical scales,
especially in Western music. In terms of harmony, the major scale is the foundation to form
the chords of a major key. The intervals for the major scale are R, M2, M3, P4, M6, M7, and
P8, or 1, 2, 3, 4, 5, 6, 7, 8.
Figure 1 – C major scale
The Natural Minor Scale
Like the major scale, the natural minor scale (or Aeolian mode) is prominent in western
music, and it is the foundation to build the chords of a minor key. The intervals for the
major scale are R, M2, m3, P4, m6, m7, and P8, or 1, 2, b3, 4, 5, b6, b7.
Figure 2 – C natural minor scale
Relative Scales/Keys
Another way of building the natural minor scale is by starting on the sixth degree of
a major scale. For instance, the A natural minor scale can be built by starting on the 6th
degree of the C major scale:
The resulting natural minor scale contains the same notes of the major scale it was built
from. Because of this, the key of A minor is called the relative minor of C major. Every
major key has a relative minor, which starts on the 6th scale degree or step. For instance,
since the 6th degree of F major is D, the relative minor of F major is D minor.
Figure 3 – C major and relative minor (A minor)
Figure 4 – F major and relative minor (D minor)
We can also build a major scale from a minor scale. For instance, the C major scale can be
built by starting on the third degree of a minor scale. In this case, the key of C major is
called the relative major of A minor.
Figure 5 – A minor relative major (C major)
Another way to find a relative major or minor is by going up or down a minor third from
the root. If you have a major scale or key, the relative minor will be a descending minor
third in relation to the root (e.g. C ↓m3 = A); if you have a minor scale or key, the relative
major will be a ascending minor third (e.g. A ↑m3 = C).
Figure 6 – Relative major and minor by m3 relationship
Building tertian chords
In tonal music, the chords are built from a succession of thirds. By stacking thirds in
succession, we are able to form the triad (R-3-5), the seventh, and the chord extensions (9,
11, 13):
Figure 7 – Tertian chords construction by adding thirds
Practicing Major and Minor Scales
Now that you know how to build scales, practice major and minor scales starting from
the same root. This is the best way to understand the intervallic difference between the
major and minor modes.
C Major Scale - Notes
C Major Scale - Intervals
C Minor Scale - Notes
C Minor Scale - Intervals
