Triadic Inversion

Musicians often prioritize the note that is in the bass voice of triadic harmonies, simply called the “bass,” which is the lowest part (or voice) of a composition, regardless of what instrument or voice type is singing or playing that lowest note. Example 1 shows an A major triad with three different notes in the bass and chord symbols (above the staff):

Example 1. An A major triad in root position, first inversion, and second inversion.

An A major triad consists of three notes, the root (A), the third (C♯), and the fifth (E). When a triad is stacked in thirds (i.e. “snowperson form”), we say the triad is in root position. The bass note in root position is the root. Chords that do not have the root in the bass are said to be inverted. As you can see in Example 1, when the third is in the bass the chord is in first inversion and when the fifth is in the bass we say the chord is in second inversion. This is shown in chord symbols with a slash followed by the letter name of the note which is in the bass.

It is important to note that the bass voice of the chord is NOT the same thing as the chord’s root. The root of an A major triad is always A, regardless of whether the triad is in root position, first inversion, or second inversion. However, the bass voice changes between these inversions, from A to C♯ to E, as seen in Example 1.

This information is summarized in Example 2:

Example 2. A summary of triadic inversions, root, and bass.

Spelling Triads in Inversion

To build an inverted triad from a chord symbol, you need to add one more step to those shown in the Triads chapter. As a reminder, these steps were:

1. Draw the root on the staff.
2. Draw notes a third and fifth above the root (i.e., draw a snowperson).
3. Think of (or write down) the major key signature of the triad’s root.
4. To spell a major triad, write any accidentals from the key signature that apply to the notes of the triad.
5. For a minor, diminished, or augmented triad, add additional accidentals to alter the chord’s third and/or fifth when appropriate.

Now we will add a sixth step:

6. Move the appropriate note to the bass to complete the triad.

Let’s complete this process for an A♭ minor triad in first inversion (A♭mi/C), as seen in Example 3:

1. The note A♭ is written because it is the root of the triad.
2. A snowperson is drawn; in other words, the notes C and E are added because they are a generic third and fifth, respectively, above A♭.
3. The key signature of A♭ major is recalled. A♭ major has four flats: B♭, E♭, A♭, and D♭.
4. E♭ is added, because it is in the key signature of A♭ major. B♭ and D♭ are not needed, because those notes aren’t in an A♭ triad. Now we have successfully spelled an A♭ major triad (A♭, C, and E♭).
5. Minor triads contain a minor third, which is one half step smaller than a major third. Therefore, our final step is to lower the chord’s third (the C) by a half step (to a C♭). Now we have an A♭ minor triad (A♭, C♭, and E♭).
6. C♭ is moved to the bass because the triad is in first inversion (A♭mi/C).

Again, following these steps is a reliable way for beginners to spell inverted triads, but it’s a time-consuming process. If you practice playing all of the qualities of triads (and seventh chords below) on an instrument until you are fluent in them, your knowledge will become more automatic without using this process.

Identifying Triads in Inversion

Triads are identified according to their root, quality, and inversion. With the addition of inversion, you can identify triads in four steps:

1. Identify and write its root.
2. Identify and write its quality.
3. Identify its inversion.
4. Write the appropriate slash and letter name.

Example 4 shows a triad in inversion (measure 1) and root position (measure 2):

Example 4. A triad in inversion (measure 1) and root position (measure 2).

The four-step process of identification for the triad in measure 1 is as follows:

1. In measure 2, the chord has been put into root position. Now we can see the root of the triad is D.
2. This triad is minor.
3. The third of the triad is in the bass; therefore this triad is in first inversion.
4. Using chord symbols, we would identify this triad as Dmi/F.

Example 5 shows another triad in inversion (measure 1) and root position (measure 2):

Example 5. A triad in inversion (measure 1) and root position (measure 2).

The four-step process of identification for the triad in measure 1 is as follows:

1. In measure 2, the chord has been put into root position. Now we can see the root is A.
2. This triad is major.
3. The fifth of the triad in the bass; therefore this triad is in second inversion.
4. Using chord symbols, we would identify this triad as A/E.

Note that the second measure of example 4 and example 5 are in parentheses. It is recommended that you imagine the chord in root position rather than write it out in order to save time.

Seventh Chord Inversion

Like triads, seventh chords can also be inverted; in other words, their root doesn’t necessarily have to be the bass. Example 6 shows an A⁷ chord in root position, first inversion, second inversion, and third inversion:

Example 6. Seventh chord inversions.

As you can see in Example 6, seventh chords have one more note than triads, so they have one additional inversion. When the chordal seventh of a seventh chord is in the bass, the chord is in third inversion. Don’t forget that the bass and the root of the chord are NOT synonymous. In Example 6 the root of the chord is always A, regardless of its inversion and bass note.

A summary of this information can be seen in Example 7:

Example 7. A summary of seventh chord inversion, root, and bass.

Spelling Seventh Chords in Inversion

To build an inverted seventh chord from a chord symbol, you need to add one more step to those shown in the Seventh Chords chapter. As a reminder, these steps were:

1. Draw the root on the staff.
2. Draw notes a third, fifth, and seventh above the root (i.e., draw an “extra-long” snowperson).
3. Think of (or write down) the major key signature of the triad’s root.
4. Write any accidentals from the key signature that apply to the remaining notes in the chord.

Now we will add a fifth step:

5. Move the appropriate note to the bass to complete the seventh chord.

Let’s complete this process for an D major major seventh chord in second inversion (Dmaj7/A), as seen in Example 8:

1. The note D, the chord’s root, is drawn on the staff.
2. An extra-long snowperson is drawn—an F, A, and C, the notes a generic third, fifth, and seventh above the D.
3. The key signature of D major has been recalled. D major has two sharps, F♯ and C♯.
4. Sharps (♯) have been added to the left of the F and the C, because F♯ and C♯ are in the key signature of D major.
5. A is moved to the bass because the seventh chord is in second inversion.

Identifying Seventh Chords in Inversion

Like triads, seventh chords are also identified according to their root, quality, and inversion. You can identify seventh chords in five steps:

1. Identify and write its root.
2. Identify and write its quality of triad.
3. Identify and write its quality of seventh.
4. Identify its inversion.
5. Write the appropriate slash and letter name.

Example 9 shows a seventh chord in inversion and the process of identification:

Example 9. A seventh chord in inversion (measure 1) and root position (measure 2).

The five-step process of identification for the seventh chord in measure 1 is as follows:

1. In measure 2, the seventh chord has been put into root position. Now we can see the root of the chord is E.
2. This triad is minor.
3. The chordal seventh is also minor.
4. The original example is in first inversion, because the third is in the bass.
5. This chord is an Emi⁷/G chord.

Another seventh chord in inversion is shown in Example 10, along with the process of identification:

Example 10. A seventh chord in inversion (measure 1) and root position (measure 2).

The five-step process of identification for the seventh chord in measure 1 is as follows:

1. In measure 2, the seventh chord has been put into root position. Now we can see the root of the chord is G.
2. The triad is major.
3. The chordal seventh is minor.
4. The original example is in third inversion, because the seventh is in the bass.
5. This chord is a G⁷/F chord.

Again, it is recommended that you imagine the chord in root position rather than write it out in order to save time (step number 1).

It is important to note that triad and seventh chord identification is not affected by the doubling or open spacing of notes, as we’ve seen in previous chapters.

• Cohn, Richard, et al. 2001. “Harmony.” Grove Music Online. https://doi.org/10.1093/gmo/9781561592630.article.50818.
• Drabkin, William. 2001. “Inversion.” Grove Music Online. https://doi.org/10.1093/gmo/9781561592630.article.13879.
• McGrain, Mark. 1986. Music Notation. Boston: Berklee Press.
• Roemer, Clinton. 1985. The Art of Music Copying: The Preparation of Music for Performance, 2nd edition. Sherman Oaks: Roerick Music Company.
  

• Understanding Inversions of Triads and Seventh Chords (Justin Rubin)
• Triad Inversion (musictheory.net)
• Seventh Chord Inversion (musictheory.net)
• How Do Chord Inversions Work? (Hello Music Theory)
• Chord Inversions (key-notes.com)
• Triad Chord Inversion (teoria)
• What are Chord Inversions? (YouTube)
• What are Chord Inversions? Piano (YouTube)
• Seventh Chord Ear Training (teoria)
• Chord Ear Training (musictheory.net)
• Chord Ear Training (Tone Savvy)

1. Triad Construction (Includes Inversion), pp. 3–4 (.pdf)
2. Triad Construction and Identification (Includes Inversion), (.pdf), pp. 4–6 (.pdf)
3. Triad Chord Identification (Includes Inversion) (.pdf)
4. Seventh Chord Construction (Includes Inversion), pp. 7–8, 11 (.pdf), p. 4 (.pdf)

1. Triadic Inversions (.pdf, .mcsz). Asks students to write chord symbols and identify the inversion of closed-position triads, and to write inverted triads from chord symbols.
2. Seventh Chord Inversions (.pdf, .mcsz) Asks students to write chord symbols and identify the inversion of closed-position seventh chords, and to write inverted seventh chords from chord symbols.