The V chord
Roman numerals in music refer to chords based on scale steps. The V chord can mean different things depending on the actual musical key. In the key of C major, the V chord is G.
Chords and intervals
The table shows how scale steps and chords are related in the key of C:
| Scales steps | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|
| Roman numerals | I | ii | ii | IV | V | vi | vii |
| Chords | C | Dm | Em | F | G | Am | Bdim |
The fifth scales step is G, which result in the G chord. Diatonically, the chord is played as a major triad, but as a dominant extended chord, such as G7 in the C major key.
In other words, the C - G - F - C and C - G7 - F - C progressions will correspond with the notes in C major whereas the C - Gmaj7 - F - C progression doesn't correspond. See Key and chord chart for more examples.
In 12-bar blues, which often involve only three chord, the V chord is normally introduced last and is played during the 9th bar and sometimes in the last bar as a turnaround.
In progressions in general, the V chord often resolve into the I chord ("the home chord"). The tension of the unstable V chord is resolve by returning home. Even more tension is created by playing a dominant V chord, V7, as in this progression: G (I) - C (IV) - D7 (V7) - G (I).
The V chord in all keys
The V chord is identical with the fifth degree of the key, a list of the fifth chord would look like this:
C major key = G major
C# major key = G# major
D major key = A major
D# major key = A# major
E major key = B major
F major key = C major
F# major key = C# major
G major key = D major
G# major key = D# major
A major key = E major
A# major key = F major
B major key = F# major
So, for example, in the key of A#, the V chord will be F.
The v chord in all keys
A similar set of relationship can be seen for the minor keys:
A minor key = Em
A# minor key = Fm
Bm minor key = F#m
Cm minor key = Gm
C#m minor key = G#m
Dm minor key = Am
D#m minor key = A#m
Em minor key = Bm
Fm minor key = Cm
F#m minor key = C#m
G minor key = Dm
G# minor key = D#m
So, for example, in the key of F minor, the v chord will be Cm. The v degree is sometimes written as Vm.
The V chord in progressions
The probably most important thing to learn is that when the V is not a triad, it's very often a dominant chord. For example, harmonizing the C major scale into four-note chords will look like this: Cmaj7 - Dm7 - Em7 - Fmaj7 - G7 - Am7 - Bm7b5. Gmaj7 would not fit with the notes in the scale
Besides the fundamental I - IV - V
progression, there are some relatively common that include a flat seven. Such as I - bV - VI, which in the key of D could be D - C - G.
See also Chord theory | Music theory | The VII chord.
