Inversions

Inversion	Bottom note	Roman numerals	Macro analysis
Root position	root: 5	V7	in C: G7
First	3rd: 7	V6 5	in C: G6 5
Second	5th: 2	V4 3	in C: G4 3
Third	7th: 4	V4 2 or V2	in C: G4 2 or G2

The opening bars of Mozart’s Piano Sonata in C, K545 features dominant seventh chords in both second and first inversions:

The concluding cadence of the same movement features the chord in root position:

A striking use of inversions of the dominant seventh can be found in this passage from the first movement of Beethoven’s String Quartet Op. 127. Here, the second and third inversions contribute to the "magnificently rich harmony" ^[9]:

Function

Tritone resolutions in the last measures of Beethoven's Piano Sonata in B♭ major, Op. 22 (1800).^[10]

The function of the dominant seventh chord is to resolve to the tonic note or chord.

... the demand of the V⁷ for resolution is, to our ears, almost inescapably compelling. The dominant seventh is, in fact, the central propulsive force in our music; it is unambiguous and unequivocal.

This dominant seventh chord is useful to composers because it contains both a major triad and the interval of a tritone. The major triad confers a very "strong" sound. The tritone is created by the co-occurrence of the fourth degree and seventh degree (e.g., in the G⁷ chord, the interval between B and F is a tritone).

In a diatonic context, the third of the chord is the leading-tone of the scale, which has a strong tendency to pull towards the tonic of the key (e.g., in C, the third of G⁷, B, is the leading tone of the key of C). The seventh of the chord acts as an upper leading-tone to the third of the scale (in C: the seventh of G⁷, F, is a half-step above and leads down to E).^[11] This, in combination with the strength of root movement by fifth, and the natural resolution of the dominant triad to the tonic triad (e.g., from GBD to CEG in the key of C major), creates a resolution with which to end a piece or a section, often in a cadence.

Because of this original usage, it also quickly became an easy way to trick the listener's ear with a deceptive cadence. The dominant seventh may work as part of a circle progression, preceded by the supertonic chord, ii.

A non-diatonic dominant seventh chord (sometimes called a chromatic seventh) can be borrowed from another key, and this can provide a way for the composer to modulate to that other key. This technique is extremely common, particularly since the Classical period, and it has led to further innovative uses of the dominant seventh chord such as secondary dominant (V⁷/V, shown below), extended dominant (V⁷/V/V), and substitute dominant (♭V⁷/V) chords.

Voice leading

For common practice voice leading or "strict resolution" of the dominant seventh chord:^[12]

• In the V⁷–I resolution, the dominant, leading note, and supertonic resolve to the tonic, whereas the subdominant resolves to the mediant.

  

• In the other resolutions, the dominant remains stationary, the leading note and supertonic resolve to the tonic, and the subdominant resolves to the mediant.

  

• All four tones may be present, though the root may be doubled and the fifth omitted.^[12][13][14]
• The diminished fifth (if the seventh is above the third, as in the first measure below) resolves inwards while the augmented fourth (if the seventh is below the third, as in the second measure below) resolves outward. This means that the seventh resolves stepwise downwards^[13][14] while the third resolves upwards to the tonic^[12] though in such cases the root of the tonic chord may need to be tripled.^[13]

  

• The root of the V⁷, when in the bass, resolves to the root of the I, in the bass.^[12]
• In an incomplete V⁷, with a missing fifth, the doubled root remains stationary.^[12]
• The "free resolution of the seventh" features the seventh in an inner voice moving stepwise upwards to the fifth of I^[12]

According to Heinrich Schenker, "The dissonance is always passing, never a chord member (Zusammenklang),'"^[15] and often (though by no means always) the voice leading suggests either a passing note:

8 7 3

5 5 1^{[further explanation needed]}

or resolution of a (hypothetical) suspension:

(8) 7 3

(4) 5 1

In blues progressions

In music that follows follow the blues progression, the IV and V chords are "almost always" dominant seventh chords (sometimes with extensions) with the tonic chord most often being a major triad. Examples include Bill Haley and the Comets' "Rock Around the Clock" and Buster Brown's "Fanny Mae", while in Chuck Berry's "Back in the U.S.A." and Loggins and Messina's "Your Mama Don't Dance" the tonic chord is also a dominant seventh.^[16] Used mostly in the first fifteen years of the rock era and now sounding somewhat "retrospective" (e.g., Oasis' "Roll With It"), other examples of tonic dominant seventh chords include Little Richard's "Lucille", The Beatles' "I Saw Her Standing There", Nilsson's "Coconut", Jim Croce's "You Don't Mess Around With Jim", and The Drifters' "On Broadway".^[16] Chuck Berry's "Rock and Roll Music" uses the dominant seventh on I, IV, and V.^[17]