As we first learned in Basic Musicianship ^[1] (which may be reviewed in the Fundamentals section), the seventh chord is a four note tertian chord, containing a fourth chord tone, the seventh. This tone is added to a triad a distance of a third above the fifth chord tone. One thing that can be somewhat confusing, at least at the beginning, are the different ways of describing the seventh chord qualities. But often we think of, and speak of, seventh chords in two parts: the chord quality of the “parent” triad and the interval quality of the seventh in relationship to the root.

There are many different ways four tones spaced by the interval of a third might be arranged and, as a result, there are eleven different qualities of the seventh chord. A complete chart of seventh chords, spellings, and ways to label may be downloaded here: Seventh Chord Encyclopedia. For the moment, we will only be concerned with the four seventh chord varieties found naturally in the major mode.

Major Mode: Seventh Chord Qualities and Labeling

Each scale degree in major will, when a seventh chord is built by stacking up four notes in thirds with the scale degree as the root,  produce different qualities of seventh chord similar to the different qualities of triads. The following chart contains each scale degree and the associated triad and seventh chord quality:

Major Mode Diatonic Triads and Seventh Chords

In context, mapped onto a specific major scale (C major), we have the following:

Figure 1. Seventh chords in the major mode (C major).

As with triads, seventh chords are labeled with both a Roman numeral analysis designation and a lead-sheet chord symbol. For scale degrees through we use upper and lower case to denote major or minor quality, and place a superscript figure number 7 to the right to indicate that the chord is a seventh chord. The differentiation of specific seventh quality is inferred by context and no further information is necessary. However, some texts try to differentiate a major-major seventh with a superscript “MA” versus a major-minor seventh, the “Dominant” seventh which often only contains the number. For scale degree , the Roman numeral label will have a circle with a diagonal slash ,  the sign for “half” diminished which is a very specific type of seventh chord: a diminished triad with a minor seventh as a chord tone in relationship to the root. In all cases, the figure number will change with inversions, explained a bit more below.

Lead sheet chord symbols are a bit more specific with regard to specifying the quality of the seventh chord. First, as we would do with a triad, the pitch class of the chord’s root is written. This is then followed by a triangle  and a superscript seven ⁷  for a major-major seventh chord, a minus sign  with a superscript ⁷ for a minor-minor seventh chord, a superscript ⁷ alone for a major-minor seventh chord (also called the “Dominant Seventh”), and a half-diminished sign  with a superscript ⁷. to indicate the half-diminished seventh chord. This particular quality of seventh chord is also referred to as a “minor seven, flat five”, particularly in the world of jazz and pop music, and is sometimes preferred. To label in this manner we write the lead sheet symbol the same way as we would a minor-minor seventh but add a superscript ^5 in parentheses after the 7 to indicate that the chord has its fifth chord tone is lowered by a half-step (colloquially speaking, “flatted”). These types of symbols, such as a flat 5 (5), are known as alterations. We will encounter more of these types of symbols as we continue to dive deeper into the world of harmony.

The Major-Major Seventh

The major-major seventh is a major triad with a major seventh chord tone in relationship to the root. This chord is colloquially referred to simply as a “major seventh” chord and is labeled in lead sheet notation with a triangle  and a superscript seven ⁷. It has a strong, robust sound which, despite the strong dissonance of the major seventh (minor second in an inversion) with the root, it has a remarkably stable and grounded sound. In the world of jazz harmony, this chord is often substituted for any primary or secondary major triad.

The Minor-Minor Seventh

The minor-minor seventh chord is a minor triad with a minor seventh chord tone in relationship to the root. Colloquially the chord is often referred to simply as a “minor seventh” chord and is labeled in lead sheet notation with a minus sign  with a superscript ⁷. It has a softer and somewhat darker sound quality than that of the major-major seventh, but, similarly, has a stable and grounded sound. As with the major-major seventh chord, in jazz it is often substituted for any primary or secondary minor triad.

The Major-Minor Seventh (“Dominant Seventh”)

The major-minor seventh chord is a major triad with a minor seventh chord tone in relationship to the root. It is almost always referred to colloquially as a “dominant seventh” chord as it is built naturally on the dominant scale degree (scale degree ). It is labeled in lead sheet notation simply with a superscript ⁷. The sound quality is quite a bit less stable and more uneasy than either the major-major seventh chord or minor-minor seventh chord owing primarily to the presence of an unstable tritone interval between the third and seventh chord tones. In tonal music, this chord, has a strong dominant function that feels a need to resolve. In jazz is often used wherever a dominant tonal function is desired.

The Half-Diminished Seventh Chord (“Minor Seven, Flat Five”)

Built naturally on the leading-tone scale degree, scale degree , the half-diminished seventh chord is a diminished triad with a minor seventh chord tone in relationship to the root. As outlined above, the chord is often referred to as a “minor seven flat five” chord. Both terms are interchangeable. It is labeled in lead sheet chord notation with either a half-diminished sign  with a superscript ⁷ or like a minor seventh chord (a minus sign  with a superscript ⁷) adding a superscript 5 in parentheses after the 7 to indicate that the chord has its fifth chord tone is lowered by a half-step. This chord is literally a minor-minor seventh chord with a lowered fifth. Like the major-minor (“dominant”) seventh chord, it also contains a tritone (between the root and fifth chord tones) and has a similarly unstable sound. However, unlike the major-minor (“dominant”) seventh, the lack of a stable perfect fifth between the root and fifth of the chord serves to soften the need for immediate resolution and as a result the chord feels more ambiguous and cloudy. It is often used as a predominant chord, especially in the minor mode for reasons we will explore later.

Inversions of the Seventh Chord

Figure 2. The inversions of the seventh chords with a C Major-Major (C7) seventh used for example.

The figure above shows a C Major-Major seventh chord (C7) in each possible inversion from root position to third inversion. As with triads, we label the inversions of each seventh chord with both a lead-sheet style chord symbol and a figured-bass number in relation to the Roman Numeral analysis. For the lead-sheet symbol, we label the chord as we do in root position and then use the slash “/” followed by the pitch class of the sounding bass tone. For the Roman Numeral figure, we use a superscript “7” for root position, “” for first inversion, “” for second inversion, and simply a “2” for third inversion. The figures (known as figured bass), as with triads, tell us where the other chord tones are in relationship to the bass–notably the root and the third of the chord in each of the inversions. A good way to remember these numbers is to think of them as part of a count down from the number seven:  7, 6-5, 4-3, 2.

Unlike the triad, we do not need to consider any additional voice-leading guidelines when using inversions of seventh chords and this includes the second inversion where we have the fifth of the chord in the bass. In a triad, this tone still needs to be handled carefully, but the seventh, owing to the dissonance that is already inherent in the chord, we need not be so careful. In short: we can use any of the inverted seventh chords anywhere we can use a root position seventh chord so long as we are fulfilling all the other voice leading requirements know to us, i.e. handling the dissonance(s), making sure we have good melodic motion with the voices, making sure our voices are properly spaced and in the proper ranges, and we aren’t engaging in perfect parallel motion between the voices, etc.

The Preparation and Resolution of the Dissonance

The dissonance, the harmonic seventh as a chord tone that sounds against the root, is handled in the same way as the diminished fifth chord tone in the diminished triad. We must first choose a chord that contains the pitch class that will become the dissonant seventh chord tone in the chord preceding. Then, after sounding the seventh chord in question, we resolve the dissonance by moving the voice containing the seventh chord tone downward by step into a chord that contains the resolving pitch as a consonant chord tone. In the case of the half-diminished seventh chord, where we have two dissonances (the seventh and the diminished fifth chord tones in relation to the root), we need to doubly prepare and doubly resolve each dissonance. Later these strict guidelines will be relaxed as our ability to enrich our harmonic phrases will increase.

Unlike the diminished triad which occurs on only the leading tone, we have the opportunity to build and use seventh chords on all seven scale degrees of the major mode. Thus, to accomplish the successful handling of the dissonant seventh, we need to locate appropriate preparation chords and resolution chords which will work with any of the available seventh chords. The chart below summarizes each of the different possible preparation and resolution schemes for each of the seventh chords we have available to us in the major mode. Later we shall adapt and modify this chart for the minor mode.

Seventh Chord Preparation and Resolution Schema

PREPARATION	SEVENTH CHORD	RESOLUTION
Dominant (V) Mediant (iii)	Tonic (I7)	SubDominant (IV)
SubMediant (vi) SubDominant (IV)	SuperTonic (ii7)	Dominant (V)
Leading-Tone (vii) Dominant (V)	Mediant (iii7)	SubMediant (vi)
Tonic (I) SubMediant (vi)	SubDominant (IV7)	Leading-Tone (vii)
SuperTonic (ii) Leading-Tone (vii)	Dominant (V7)	Tonic (I)
Mediant (iii) Tonic (I)	SubMediant (vi7)	SuperTonic (ii)
SubDominant (IV) SuperTonic (ii)	Leading-Tone (vii7)	Mediant (iii)

Connecting Seventh Chords to Other Seventh Chords

The connection of two or more seventh chords to one another is absolutely possible, and even sometimes quite desirable as  often these connections create smooth voice leading. There are no special conditions or guidelines involving the connection of sevenths to one another so long as one is careful to prepare and resolve each of the sevenths (and the diminished fifth in the half-diminished seventh). While a sequence of seventh chords may have excellent results, one must be careful not to overuse them so as not to create a lack of variety. A good musical phrase, at least in this context, will contain a balance of sevenths and triads in different inversions, ultimately producing good melodic results in the soprano and a good melodic bass line (and, if possible, good inner voice counterpoint!).

Summary

We may summarize what we learned above in three step process as follows:

1. Prepare the dissonant seventh chord tone by sounding it first in a preceding chord as a consonant tone and then tying it over as a common tone. For the leading tone half diminished seventh, we need to prepare both the seventh and the diminished fifth dissonances. Use the chart above to refer to chords that could be used to prepare a seventh on any given scale degree in the major mode.
2. Sound the seventh chord by holding over the dissonance(s) and any other common tones, then moving the other voices to the next nearest chord tones to complete the chord. As we are sounding a seventh chord, no doubling is necessary. However, we do need to make sure we have a complete chord. For now, do not omit any chord tones (later we will be able to relax this condition).
3. Resolve the dissonance(s) by moving to the resolution chord and moving the voice containing the dissonant seventh chord tone (or both the seventh and the diminished fifth) downward by step, holding over any tones in common, and moving the other voices to the nearest available chord tones. Again, mindful of trying to double the root when possible when moving to a triad.
4. When resolving to a triad, move to the resolution chord found in the chart which is, for now, always found a root motion of a fourth upward from the scale degree on which we sounded the seventh chord. The concept of relative root motions of  chords in harmonic progressions is a very important one and will become more and more important as we move further in our study.
5. It is possible, and sometimes desirable, to connect sevenths to one another. There are no special additional guidelines for this so long as you are able to properly prepare and resolve the dissonance(s) and also satisfy quality voice leading with all of the guidelines we’ve covered and discussed thus far.

Chord Connection Guidelines: V4

Now that we have added seventh chords to the mix, we can add and adjust our tonal harmony progression flowchart:

Common Tone Chord Chart (Major Mode)

Seventh Chord Preparation and Resolution Schema

PREPARATION	SEVENTH CHORD	RESOLUTION
Dominant (V) Mediant (iii)	Tonic (I7)	SubDominant (IV)
SubMediant (vi) SubDominant (IV)	SuperTonic (ii7)	Dominant (V)
Leading-Tone (vii) Dominant (V)	Mediant (iii7)	SubMediant (vi)
Tonic (I) SubMediant (vi)	SubDominant (IV7)	Leading-Tone (vii)
SuperTonic (ii) Leading-Tone (vii)	Dominant (V7)	Tonic (I)
Mediant (iii) Tonic (I)	SubMediant (vi7)	SuperTonic (ii)
SubDominant (IV) SuperTonic (ii)	Leading-Tone (vii7)	Mediant (iii)