Chords and Chord Progressions

Chords:

What is a chord?
3 or more notes played together, or one after another (arpeggiated chords).
In western music, this involves notes constructed in thirds apart. With notes a third apart from each other, they are going to be stacked on top of each other on either lines or spaces.

Creating triads with 3 pitches:

These will tend to be Major, Minor, Augmented or Diminished chords.

Triads are made of the root, the third and the fifth.
The first note is the root, the second note is the third, and the last note in the chord is the fifth.
The third in the chord is very important because it determines if you are in a major or minor key (the quality).

Building triads by counting semitones and scale degrees:

Major- Root position + 4 semitones + 3 semitones (7 semitones above the root)
1, 3, 5

Minor- Root position + 3 semitones + 4 semitones (7 semitones above the root)
1, b3, 5

Augmented- Root position + 4 semitones + 4 semitones (8 semitones above the root)
1, 3, #5

Diminished- Root position + 3 semitones + 3 semitones (6 semitones above the root)
1, b3, b5

Here is a major triad in Bb major.

Seventh chords:

This is when you add another third above the 5th of the triad. They are called 7ths because it is the 7th interval from the root.

You can get many types of sevenths:

Major

Minor

Dominant sevenths

Minor 7 flat 5 chords (half-diminished chords)

Diminished 7ths
Minor-major 7ths

Building 7ths by counting semitones:

Major-   Root + 4 semitones + 3 semitones + 4 semitones (11 semitones above the root)
1, 3, 5, 7


Minor-   Root + 3 semitones + 4 semitones + 3 semitones (10 semitones above root)
1, b3, 5, b7


Dominant-   Root + 4 semitones + 3 semitones + 3 semitones (10 semitones above)
1, 3, 5, b7


Minor 7 flat 5-   Root + 3 semitones + 3 semitones + 4 semitones (10 semitones above root)
1, b3, b5, b7


Diminished-   Root + 3 semitones + 3 semitones + 3 semitones (9 semitones above root)
1, b3, b5, bb7


Minor-major-   Root + 3 semitones + 4 semitones + 4 semitones (10 semitones above root)
1, b3, 5, 7

Inverted chords:

This is if the lowest sounding pitch is not the root. Here are the possible inversions:

First inversion:

If the third of the chord is lowest sounding. 

Second inversion:

When the fifth of the chord is the lowest sounding note.

Third Inversion:

When the seventh of the chord is the lowest sounding note. 

Chord Progressions:

Chords built on the seven notes of a major key signature are called diatonic chords. Chords that are built up on notes outside the key signature are called chromatic chords.

This is a bit different with minor scales, as you can get relative and harmonic minor scales too. This means there is actually 9 different 9 notes that can fit in a minor scale. You can think of there just being 1 minor scale, just that they have the flexibility of the 6th and 7th degrees of the scale.

Chord progressions are chords which are played in a succession.
Roman numerals can be used to represent the different scale degrees. Roman numerals in capitals represent major chords and lower case roman numerals represent minor chords. You can also get other signs to indicate whether the chord is diminished (o) or augmented (+).


Chord names within a C maj scale:                          Note:

1  Tonic                                                                  C
2  Supertonic                                                           D
3  Mediant                                                               E
4  Subdominant                                                        F
5 Dominant                                                             G
6 Submediant                                                          A
7 Leading tone                                                        B
8/1 Tonic                                                                C

The image above shows the triads contained within the key of C major.

Common Major Key Chord Progressions:

Chord                          Leads To

I                                  Can appear anywhere and lead anywhere
ii                                  I, V,  or viidim
iii                                 I, IV, vi
IV                               I, ii, V, or viidim
V                                I or vi
vi                                I, ii, iii, iii, IV, or V
viidim                          I


Chord progressions in minor keys:
Here, the 6th and 7th degrees of the scale are variable, depending on whether the natural, harmonic or melodic minor are used in the music. The possible chords within C minor are:

Cm- C, E, G             i
Ddim- D, F, Ab        iio
Dm- D, F, A             ii
EbM- Eb, G, Bb       III
Eb aug- Eb, G, B      III+
Fm- F, Ab, C           iv
FM- F, A, C            IV
Gm- G, Bb, D          v
GM- G, B, D           V
AbM- Ab, C, Eb     VI
A dim- A, C, Eb      #vio
BbM- Bb, D, F        VII
Bdim- B, D, F          #viio
Cm- C, Eb, G          i


Common Minor Key Chord Progressions:
Chord                                              Leads To
i                                                       Can appear anywhere and lead anywhere
iio                                                     i, V (v), or vii (VII)
III (III+)                                           i, iv, (IV), VI (#vio), or viio (VI)
iv (IV)                                              i, V (v), or viio (VII)
V(v)                                                 i or VI (#vio)
VI (#vio)                                          i, III (III+), iv (IV), V (v), or viio (VII)
viio (VII)                                          i

Here is the Czardas score with me looking at chords on it:

It uses a lot of dominant A7 chords so that it can then resolve onto D with a perfect cadence.

Modulating to a new key:

This is when a piece of music temporarily moves into a new key. The moving is the modulation.

Cadence:

A cadence is a place where it feels like an ending. It can be a strong stopping point.

There are 4 types of cadences:

-Authentic cadence
-Plagal cadence
-Deceptive cadence
-Half cadence

Authentic cadences:

There are 2 types of authentic cadences:  Perfect cadence and imperfect cadence

Perfect cadence- chord V to chord I in root position. At its strongest when the root is at the bottom and top of the stack of notes.

Imperfect cadence- A V-I chord progression made with inverted chords (where the root, the third, and the fifth aren't in the perfect stack of notes).


Plagal cadences (Amen cadence):

These cadences go from IV (iv) to chord I (i).

Possible plagal cadences would include IV-I, iv-i, iv-I, IV-i.

Deceptive/interrupted cadence:

Reaches the ultimate point of tension on a V chord like an authentic cadence but then it doesn't resolve on the tonic but resolves onto any other chord. It is interrupted because you think it is going to resolve on the tonic, but it doesn't.  It has the feeling of incompleteness.

The most common interrupted cadence is a chord V leading onto a VI chord.

Half cadence/imperfect:

This cadence ends at the point of tension (the V chord) and stops, resulting in the music feeling unfinished.

The mos common way that this happens is when chord I is in second inversion (when the fifth of the chord is the lowest sounding note). This produces different chords with the same bass note.