Chapter 2
Chords are the building blocks of harmony, consisting of multiple notes played simultaneously. There are no inherently good or bad chords—just different sounds. Consonance or dissonance is subjective, depending on the listener's perception. Just as beauty is in the eye of the beholder, so are sounds in the ear of the beholder. Whether a chord sounds consonant or dissonant is up to you.
Some note combinations naturally occur within the harmonic series of each musical note. These combinations within a single note's structure are fundamental to how we perceive consonance and dissonance. Consonance is typically associated with pleasantness, stability, and repose, while dissonance is linked to tension and conflict, often sounding grating and giving a sense of incompleteness and unease. However, these terms are not static; music involves the movement between sounds, and consonance and dissonance are two sides of the same coin.
Notes can be combined in various ways to form different chords, with universally accepted classifications for the most common chord combinations.
In this section, we examine three-note combinations, known as triad chords, which are the basic building blocks of Western music.
Later, in the section on inversions, we will show how to rearrange the notes of a standard triad chord to maximize hand movement efficiency when transitioning quickly between chords.
Triad chord note combinations did not happen just by accident. Triad chord combinations are based on the close harmonic relationships found in the harmonic series.
The first note of a chord is called the "root," while the first note of a scale or key is called the "tonic."
Major Chords
The harmonics 4X, 5X, and 6X of a root note naturally produce the notes of its major chord.
These harmonics, being naturally occurring from the root note, should sound harmonious when played together. Essentially, any individual note's 4X, 5X, and 6X harmonics form its major chord.
A chord is classified as major if the interval between the root and the middle note is a major third and the interval between the middle and third notes is a minor third.
Specifically:
The interval 5X/4X represents a major third.
The interval 6X/5X represents a minor third.
As explained in the section on large intervals, combining a major third interval with a minor third interval forms a major chord.
Key Takeaway
A major third interval combined with a minor third interval forms a major chord.
A major chord is built by stacking intervals: starting from the root note, you add a major third interval to reach the second note, then a minor third interval to reach the third note. This structure creates the stable and harmonious sound characteristic of major chords.
Forming a Major Chord
A major third interval combined with a minor third interval forms a major chord.
Root Note: The starting note of the chord. In our example, it is C.
Major Third Interval: From the root note (C), count up four half-steps to reach the major third note (E).
Minor Third Interval: From the major third note (E), count up three half-steps to reach the perfect fifth note (G).
When you combine these intervals:
The root note (C) to the major third (E) is a major third interval.
The major third (E) to the perfect fifth (G) is a minor third interval.
This combination of a major third interval followed by a minor third interval forms the complete major chord:
C (root note)
E (major third)
G (perfect fifth)
Minor Chords
A minor chord is a type of triad (a three-note chord) that has a specific structure, giving it a distinct sound that is often described as sad, melancholic, or somber. The formation of a minor chord involves combining specific intervals from a root note.
The harmonics 10X, 12X, and 15X of a note naturally produce the notes of a minor chord. For example, for the note C, these harmonics correspond to the notes E, G, and B. This combination of notes forms an E minor chord.
Classification of a Minor Chord
A chord is classified as minor if:
The interval between the root and the middle note is a minor third.
The interval between the middle note and the highest note is a major third.
This structure is the reverse of a major chord, where a major third interval comes first, followed by a minor third interval.
Forming Minor Chords
In the D minor chord shown here the middle note, F, is a minor third above the root note, D.
A minor third interval spans four semitones.
Put simply, two keys separate a minor third
The third note, A, is a major third above the middle note, F.
A major third interval spans five semitones, meaning three keys separate a major third
In a minor chord, the intervals are the same as in a major chord but reversed. A minor third interval and a major third interval define a chord as minor. Therefore, the D chord shown here is minor.
In major keys, the two and three-semitone separation also applies to chords formed on scale degree positions 2, 3, and 6, as shown below.
Remember: In major keys, minor chords are formed on scale positions 2, 3, and 6.
Diminished Chords
A diminished chord has a tense and unstable sound. Diminished chords are often used in music to transition between other chords, acting like a bridge that can create a sense of movement or change in the harmony. Because of their unresolved sound, they are not typically used as the final chord of a piece.
Structure:
A diminished chord is made up of three notes, and it is built using two intervals:
A minor third: This is an interval of three semitones (three half steps) from the root note.
Another minor third: This is an interval of three semitones above the previous note.
"Diminished" means to make smaller.
In the B diminished chord shown here:
The middle note, D, is a minor third above the root note, B.
A minor third interval spans four semitones.
Put simply, there are two keys between the root and middle notes.
Another minor third separates the middle note, D, from the third note, F.
Similarly, this interval also spans four semitones.
This diminished chord, found on the seventh scale position of a major key, is unique. Only in this position do we see the pattern of two minor third intervals, creating a "two and two" separation in the major key.
Rules for forming Major & Minor Chords
Major/Minor Chords Using the Rectangle:
Rule for Major/Minor Triad Chords:
For chords with the root note on a white key:
The third note is also on a white key.
There are three white keys between the root and the third note.
For chords with the root note on a black key:
The third note is also on a black key.
There are two black keys between the root and the third note.
General Pattern:
The third note of a triad chord is always one keyboard position value higher than the root note's keyboard position value - this will make more sense when we discuss the rectangle of fifths.
Exceptions:
Triad Chords with root on white keyboard position 5 (B) have their third note on a black position. Triad chords with root on the black keyboard position 5 (B♭) have their third note on a white position.
