9 Ear Training – Triads

Triads and Their Inversions

A triad, as the name suggests, is a chord composed of three tones.

The major triad is composed of (from lowest to highest pitch) a stacked major third plus minor third.

The two commonest ways the major triad appears in diatonic harmony are (a) as the tonic chord (I) in a major key (do-mi-sol), and (b) as chord V (sol-ti-re), which is the same for major and minor keys. It’s also very common for the major triad to appear as chord IV in major keys (fa-la-do).

The minor triad is composed of a stacked minor third plus major third.

In minor keys, the minor triad appears most commonly as chord i (do-me-sol), and also as chord iv (fa-le-do). In major keys, the minor triad appears commonly as chord ii (re-fa-la) and as chord vi (la-do-mi).

The diminished triad is composed of two stacked minor thirds.

The diminished triad functions as chord vii⁰ in both major and minor keys. In minor keys, the diminished triad also functions as chord ii⁰.

First-time learners are often tempted to sing the diminished triad using the solfege do-me-se, but this spelling has no functional context in diatonic music. Not all chords begin on do! It’s also very hard to sing do-me-se. Singing ti-re-fa is much easier because of its common context in diatonic music.

The augmented triad is composed of two stacked major thirds.

The augmented triad is relatively rare in diatonic harmony. It doesn’t naturally occur within the tones of the diatonic major scale, and sounds very dissonant. For this reason, many learners find it hard to sing. When it does occur, it is usually spelled sol-ti-ri and appears as a chromatic variant of the dominant (sol-ti-re). We also find it as chord III⁺ in harmonic minor; again, this is relatively rare.

Some learners confuse the diminished and augmented triads, because they (rightly) hear them both as dissonances. The best way to learn to differentiate between them is to find relatable contexts. For example, the diminished triad has a strong “pull” towards tonic harmony and the resolution of dissonance into consonance. The augmented triad, by contrast, doesn’t have that harmonic context. If you think you are hearing an augmented triad, ask yourself what it would sound like if the top tone of the chord went down half a step. That should leave you with a major triad. Singing the exercises below should also familiarize you with the characteristics and functions of the four types of triad.

Memorizing Triads and Their Functions in Root Position

Sing and memorize the following excerpt, which teaches the four types of triad and their common solfege and function.

Inverting the Triads

When we spell a triad in such a way that the lowest pitch is a note other than the root of the triad, we say that it is inverted. Because triads have three pitches, there are two possible inversions, which we call first inversion and second inversion.

Triads in root position are composed of a first, third, and fifth degree, hence the term “5/3” for root position. Triads in first inversion are composed of first, third, and sixth degree, and are identified as “6/3,” which gets abbreviated to “6.” Triads in second inversion are composed of a first, fourth, and sixth degree, and are identified as “6/4.”

The following example shows a major triad in root position, first inversion, and second inversion. The degrees of the chord, and their abbreviations, are shown below the staff.

Commit the following chart to memory. It describes the terminology of how we spell the triad and its first and second inversions, including common abbreviations used to notate figured bass.

Identifying Triads in Inversion

Step 1:

• Listen to the “color” of the triad. Often you will be able to tell the chord quality from only one hearing. Major and minor tend to be unmistakable because they are so familiar to most people. Be careful, however, to distinguish between augmented and diminished triads, the two dissonant ones. If unsure, listen contextually, using your solfege and diatonic harmonic logic.

Step 2:

• Listen to the triad intervallically. An inverted triad will have some kind of fourth (a larger interval than a third) in it. In major and minor, there will be a perfect fourth. In a diminished triad, there will be an augmented fourth. In an augmented triad, the symmetricality of the chord means that all intervals will “sound like” major thirds, regardless of the inversion and notation, because a diminished fourth is enharmonically equivalent to a major third.

First Inversion (6/3) Triads in Context

• Major 6/3 is composed of a stacked minor third + perfect fourth
• Minor 6/3 is composed of a stacked major third + perfect fourth
• Diminished 6/3 is composed of a stacked minor third + augmented fourth
• Augmented 6/3 is composed of a stacked major third + diminished fourth…but in this class, you can identify and notate it as 5/3 only because of its “symmetrical” nature. In an ear training assignment, you would not be expected to tell the difference between a root position augmented triad and an augmented triad in first inversion, because the major third and the diminished fourth are each other’s enharmonic equivalent. In other words…there is no way to tell them apart when you hear a chord in isolation.

Confusing root position with first inversion? This easy song helps to internalize the four different types of triad, their harmonic contexts, and their first inversions.

As always, well-known repertoire provides memorable contexts for inverted triads. The famous trumpet solo from Stravinsky’s Petrushka outlines a major triad in first inversion.

Second Inversion (6/4) Triads in Context

In the early stages of chord and inversion identification, learners often confuse 6/3 and 6/4 triads. If you are confused, listen carefully for the presence of the larger interval, i.e. the fourth. In major and minor triads, the fourth will be perfect; in diminished triads, it will be an augmented fourth. In second inversion triads, the two lowest pitches will form the larger interval.

Study and listen to these common contexts for second inversion triads. In the first example, the opening of the second movement of Beethoven’s Symphony No. 5, the first three pitches of the melody form an ascending second inversion major triad.

By contrast, study and listen to the opening of Brahms’s Hungarian Dance No. 5. This piece is in the key of G minor. The first three pitches of the melody outline the tones of the second inversion minor triad (in ascending motion).

Listen to the Spotify playlist several times until you know both compositions well. Also in the playlist is Chopin’s “Raindrop” Prelude, a famous example of the the major 6/4 triad played in descending motion. Can you sing along in solfege?