themusictheorycourse.comFree online lesson, with sound and self-correcting exercises
B.2Supplement B, Chords
Triads
This lesson shows you how to tell apart the four types of triads, which scale degrees carry them in major and in minor, and how to find the keys a given triad can belong to.
10 min8 questionsDanhauser § 295 and 296
Let's build a triad on every degree of the major scale, then of the minor scale. For minor, we use the form with the leading tone and the minor sixth, that is, the harmonic minor that Danhauser studies. When you sort these chords by their intervals, you find four types (§ 295).
Type
Intervals above the root
Name
Major mode
Minor mode
1st
major third and perfect fifth
major triad
I, IV, V
V, VI
2nd
minor third and perfect fifth
minor triad
ii, iii, vi
i, iv
3rd
minor third and diminished fifth
diminished triad
vii°
ii°, vii°
4th
major third and augmented fifth
augmented triad
none
III+
The four types of triads.
Triads on the degrees of C major: I, IV and V are major; ii, iii and vi are minor; vii° is diminished.Triads on the degrees of A minor, with the leading tone G#: i and iv are minor, V and VI are major, ii° and vii° are diminished, and III+ is augmented.
Finding the keys a chord can belong to
Now that you know the four types, let's turn the question around. The same chord belongs to several keys. Danhauser's example is the chord A, C#, E (§ 296), shown here in first inversion, with C# in the bass. It's a major triad with A as its root. A major triad sits on degree 1, 4 or 5 in major, or on degree 5 or 6 in minor. So it can be:
I in A major;
V in D major or D minor;
IV in E major;
VI in C# minor.
The chord from § 296: C# is in the bass, and the root is A.
Listen to the triad on each degree, first in major, then in minor.
Tonic
Mode
Chords
Inversion
Degree
Notes
Quality
Symbol
I · tonic
C E G
major triad
C
ii · supertonic
D F A
minor triad
Dm
iii · mediant
E G B
minor triad
Em
IV · subdominant
F A C
major triad
F
V · dominant
G B D
major triad
G
vi · submediant
A C E
minor triad
Am
vii° · leading tone
B D F
diminished triad
B°
Position : 5/3 (root position).
Exercisein the method's spirit
Name the keys each of the following triads can belong to and, in each key, the degree it sits on in root position: a) E, G, B b) B, D, F c) F, A, C d) C, E, G#.
Solution
a) This is a minor triad on E: ii of D major, iii of C major, vi of G major, i of E minor and iv of B minor. b) This is a diminished triad on B: vii° of C major, ii° of A minor and vii° of C minor. c) This is a major triad on F: I of F major, IV of C major, V of B-flat major and B-flat minor, and VI of A minor. d) This is an augmented triad on C: III+ of A minor, and that's the only possibility.
You've met the four types of triads. In the next lesson, we'll add one more third on top and discover seventh chords. Before that, try these questions.
Check your understanding
8 questions
1.
What are the intervals of a minor triad?
2.
In major, which degree carries the diminished triad?
3.
Which degree of harmonic minor carries the augmented triad?
4.
What type of triad is this?
5.
The chord G, B, D can be V of:
6.
In A minor (harmonic), the triad on the 5th degree is:
7.
The symbol Bdim (or B°) stands for:
8.
In which key is the chord F, A, C on the 6th degree?
A lesson is completed automatically at 70% on the quiz. You can also mark it yourself.
A question, a mistake, a word about this lesson? Write to us.