Music Chords
Intervals and Stacking ThirdsIn this session, we will be looking at a general overview of different music chords and the intervals used to make up these chords.
Chords are made up of 2 or more notes played simultaneously.
A power chord is a form of 2-note chord, consisting of the root note and a perfect 5th. The chord formula for a power chord is 1 - 5 (1st & 5th)
The most common chords are triads which are 3-note chords that are usually major, minor, suspended, augmented and diminished chords. These chords can be extended by adding notes forming seventh, ninth, eleventh and thirteenth chords.
Chords are generally classed by their root note; so for example, a C chord is built upwards from the keynote of C.
Music Notes & Chords
Music Chords have collective names, depending on the number of notes in the chord:
- Dyad - 2 note chord
- Triad - 3 note chord (most common)
- Tetrad - 4 note chord
- Pentad - 5 note chord
- Hexad - 6 note chord
Stacking Thirds
The majority of music chords are made up of thirds stacked on top of each other. They are either major thirds or minor thirds.
- A major third is equal to 4 half steps or 4 semitones ( 2 tones)
- A minor third is equal to 3 half steps or 3 semitones (1+1/2 tones)
Let us look at the 4 common triads: Major, Minor, Diminished and Augmented triads. (We will illustrate using the scale of C Major) We will also use a chromatic scale which means we play all the notes in half steps or semitones which is the shortest distance between notes.
1. Major Triad = Major third + Minor third:
C - C# - D - D# - E - F - F# - G
- Take C and count 4 half-steps upwards and reach E.
- Take E and count 3 half steps upwards and reach G... You have a C Major Triad (C)
- From C - G is a Perfect 5th or 7 half-steps
2. Minor Triad = Minor third + Major third:
C - D♭ - D - E♭ - E - F - G♭- G
- Take C and count 3 half-steps upwards and reach E♭
- Take E♭ and count 4 half steps upwards and reach G... You have a C Minor Triad (Cm)
- From C - G is a Perfect 5th or 7 half-steps
3. Diminished Triad = Minor third + Minor third...
C - D♭ - D - E♭ - E - F - G♭
- Take C and count 3 half-steps upwards and reach E♭.
- Take E♭ and count 3 half steps upwards and reach G♭... You have a C Diminished Triad (Cdim)
- From C - G♭ is a Diminished 5th or 6 half-steps
4. Augmented Triad = Major third + Major third...
C - C# - D - D# - E - F - F# - G - G#
- Take C and count 4 half-steps upwards and reach E
- Take E and count 4 half steps upwards and reach G#... You have a C Augmented Triad (C aug)
- From C - G# is an Augmented 5th or 8 half-steps
If you continue to stack major and minor thirds on a triad you end up with 7th's. If you stack them on 7th's, you get 9th's; stack them on 9th's, you get 11th's; stack them on 11th's you get 13th's... that's a lot of stacking!
It is important to understand the concept of stacking thirds when working with intervals. If you understand the stacking of thirds in forming triads, you are well on your way to understanding intervals in more complex music chords. C'mon, you're doing great!
In popular music, a music chord is composed of several parts:
- The root note (e.g., C)
- The chord type (e.g., major, minor, suspended, augmented , diminished)
- The number of an interval (e.g., 3rd, 5th, 7th)
- The altered interval (e.g., ♭3, #5, ♭7)
- An additional interval number (e.g., Dadd4, Cadd9, C/9 )
Commonly used Triads:
Triads are three-note chords made up of the 1st, 3rd, and 5th notes of a scale. The four basic types of triads are major, minor, diminished, and augmented.
The following chart is based on the C Major Scale:
C - D - E - F - G - A - B
| Chord Type | 3rd Interval | 5th Interval | Chord | Notes |
|---|---|---|---|---|
| Major Triad (C) | Major 3rd | Perfect | C, CM, CΔ, Cma, Cmaj | C - E - G |
| Minor Triad (Cm) | Minor 3rd | Perfect | Cm, C-, Cmi, Cmin | C - E♭ - G |
| Augmented Triad (C+) | Major 3rd | Augmented | C+, Caug | C - E - G♯ |
| Diminished Triad (Cº) | Minor 3rd | Diminished | Cº, Cm(♭5), Cdim | C - E♭ - G♭ |
Commonly used 7th Chords:
Seventh chords, or tetrads, are four-note chords that include the 1st, 3rd, 5th, and 7th notes of a scale. They are formed by adding a fourth note to a triad (a three-note chord). This additional note is a third above the fifth of the triad, creating an interval of a seventh above the root of the chord.
The following chart is based on the C Major Scale:
C - D - E - F - G - A - B
| Chord Type | 3rd Interval | 5th Interval | 7th Interval | Chord | Notes |
|---|---|---|---|---|---|
| Dominant 7th | Major 3rd | Perfect | Minor | C7, C7, Cdom | C - E - G - B♭ |
| Minor 7th | Minor 3rd | Perfect | Minor | Cm7, Cmin7, C−7 | C - E♭ - G - B♭ |
| Major 7th | Major 3rd | Perfect | Major | Cmaj7,CM7, CΔ7 | C - E - G - B |
| Minor major 7th | Minor 3rd | Perfect | Major | Cm(M7), C−M7 | C - E♭ - G - B |
| Augmented 7th | Major 3rd | Augmented | Minor | C+7, Caug7, C7+, C7+5 | C - E - G# - B♭ |
| Augmented major 7th | Major 3rd | Augmented | Major | C+(M7), CM7+5, CM7♯5 | C - E - G# - B |
| Diminished 7th | Minor 3rd | Diminished | Diminished | Cº7, Cdim7 | C - E♭ - G♭ - B♭♭ |
| Diminished half-7th | Minor 3rd | Diminished | Minor | Cø7, Cm7♭5, C−7(♭5) | C - E♭ - G♭ - B♭ |
Extended Chords - 9th, 11th & 13th chords
Extended chords build on triads (three-note chords) by adding additional notes beyond the 7th. These extensions include 9th, 11th, and 13th chords. Notes added beyond the 13th typically repeat notes that are already present in the chord.The following will help to explain this.
- A 9th is like a suspended 2nd (sus2) but the 2nd is played an octave higher.
C - D - E - F - G - A - B♭ - C - D - An 11th is like a suspended 4th (sus4) but the 4th is played an octave higher.
C - D - E - F - G - A - B♭ - C - D - E - F - A 13th is like a 6th but the 6th is played an octave higher.
C - D - E - F - G - A - B♭ - C - D - E - F - G - A
A 3rd above the last A on the 13th chord (A - B - C) will take you back to C (the root or tonic)... we start all over again so there is no point in going any further with 15th's, 17th's etc.
In summary, triads, 7th's, 9th's, 11th's, and 13th's take care of every note in a given music scale.
The following chart is based on the C Major Scale:
C - D - E - F - G - A - B
| Chord Type | 3rd, 5th, 7th Interval | 9th | 11th Interval | 13th | Chord | Notes |
|---|---|---|---|---|---|---|
| Dominant 9th | dominant 7th chord | Major | - | - | C9 | C - E - G - B♭ - D |
| Dominant 11th | dominant 7th chord | Major | Perfect | - | C11 | C - E - G - B♭ - D - F |
| Dominant 13th | dominant 7th chord | Major | Perfect | Major | C13 | C - E - G - B♭ - D - F - A |
Notice that 9th, 11th and 13th chords are built on dominant 7th chords where the 7th degree of the scale is flattened. Also notice that,
- a 9th chord can be written as
C7add9 or C7/9 (notes are C - E - G - B♭- D)
not Cadd9 or C/9... where the notes are C - E - G - D - an 11th chord can be written as C9 add11 or C9/11 (notes are C - E - G - B♭- D - F)
- a 13th chord can be written as C11 add13 or C11/13 (notes are C - E - G - B♭- D - F - A)
Suspended Chords
A sus chord or suspended chord is a 3 note chord or triad where the 3rd is omitted. This is replaced with a major 2nd or a perfect 4th. It is a music chord having a root, a major 2nd or perfect fourth (no third), and a perfect fifth. This results in two main chord types:
- the suspended second (sus2) - A Major 2nd is 2 half-steps or semitones upwards from the root or tonic
- the suspended fourth (sus4) - A Perfect Fourth is 5 half-steps or semitones upwards from the root or tonic
For example, the chord Csus2 consists of the notes C - D - G, while Csus4 consists of the notes C F G, respectively.
Take Note
- When you are counting upwards from a note, don't include the first note, e.g., a major 3rd is 4 half- steps upwards from the tonic or root, so a major 3rd (four half-steps) from C is E:
C - C# - D - D# - E. We count upwards from C, not counting C - When we talk about intervals or notes in a scale or chord, we refer to them as the 3rd, 5th, 7th notes etc. In these cases, we include the tonic or root note when counting, therefore the 5th note of a C Major scale or chord is G: C - D - E - F - G (C or first note is included in the count).
