Ear Training - Mastery of Triads and Their Inversions

The Theory of Triads

In Unit 2, we studied the four different types of triads and their harmonic contexts. You must be able to recognize and notate the triads in their inversions. Review the recognition methods for triads in the table below.

Chord Quality	Major	Minor	Diminished	Augmented
Most common solfege	do mi sol or sol ti re	do me sol or re fa la or la do mi	ti re fa	sol ti ri or me sol ti
Most common context	I in major keys; V in major and minor keys	i in minor keys; ii or vi in major keys	viio7 in major and minor keys	(rare) can be a variant of chord V; chord III+ in harmonic minor

Notice the Inversion Major, minor, and diminished triads in inversion should be easy to identify because there will be a larger interval that you will be able to hear especially when the triad is arpeggiated.

• For major and minor triads, that interval will be the perfect fourth that appears between do and sol.
• For diminished triads, you will hear the augmented fourth that appears between fa and ti.
• Augmented triads are a special case. Because an augmented triad is composed of two major thirds, when it is inverted, you aren’t expected to hear whether the larger interval is a major third vs. a diminished fourth because those two intervals are enharmonically equivalent. Therefore, for the purposes of this class, you may feel free to identify and notate augmented triads as root position only. (If you choose to identify them as inverted, your notation must be consistent with your analysis for full points.)

Things To Listen For When listeners are under pressure (such as in a quiz or exam), they sometimes confuse diminished and augmented triads. Here are some tips for differentiating them.

• Diminished triads are composed of stacked minor thirds. Augmented triads are composed of stacked major thirds. If you hear what you think is an augmented triad (sol ti ri), imagine the highest pitch down a half step (in other words, make it into the familiar dominant triad, sol ti re). If that leaves you with a major triad, you know augmented is correct.
• When inverted, diminished triads will contain one smaller and one larger interval (i.e. a minor third and an augmented fourth, not necessarily in that order). No matter which way an augmented triad is inverted, it never contains unequal-sounding intervals.
• The diminished triad is used for very specific harmonic functions in diatonic music, i.e. chord vii^o in both major and minor keys (and chord ii^o in minor keys). The augmented triad, by contrast, is not used very often in diatonic music and does not have a commonly-used function. Listen for the chord with the more common context.