Dominant 7th chords

In a "seventh chord" — more precisely a dominant 7th (V7) — you add a minor 7th to a major triad. In C7 that note is Bb, not B. In a maj7 chord you add a major 7th; in Cmaj7 that’s B instead, not Bb. More about maj7 chords in the lesson on maj7 chords.

Rather than counting up seven scale steps, count down a half step (maj7) or a whole step (7) from the root:
C → B → Bb.

To add a 7th to the “classic” G major chord, take the root G on the high E string and lower it by two frets to get the seventh F.

Drag the slider under the chord diagram(s) to the right to turn G into G7. You can also display intervals and note names and watch how the shape is changing.

To modify the G barre chord, lower the root on the D string by two frets to get the 7th (F).

Additionally, you can raise the fifth (5) on the B string by three frets (half steps) to get a 7th. We already used that approach in the minor 7th lesson.

Move this shape as a whole to form other dominant 7th chords with the root on the low E string.

In the “classic” C major chord shape, you can’t lower the C on the B string by two frets to Bb (the 7th). Instead, raise the 5th (open G string) by three frets.

If the shape contains only one fifth you can still raise it. It’s fine to omit the fifth in a seventh chord (not in chords with ♭5 or #5). The root, third and seventh define the chord’s character.

You can also take the C major barre chord and lower the C on the G string by two frets.

Move this shape as a whole to form other dominant 7th chords with the root on the A string, such as A7 or Bb7.

Turn D major into D7 like this…

This shape can also be moved like a barre chord to get other V7 chords with the root on the D string (e.g., Eb7).

Why is it called a dominant 7th (V7) chord?

When we stack thirds over each note of a major scale (using only scale tones), we obtain the scale’s diatonic chords. Depending on how many thirds we stack, we get triads, seventh chords, etc.

A major chord with a minor 7th appears only on the 5th (V) scale degree — the dominant. Hence the name dominant seventh or V7 chord.

In practice — depending on the harmonic context — you’ll often find V7 chords on other degrees as well, without changing the main key.

More chord shapes

There are many usable shapes for dominant 7th chords. The root doesn’t always have to be the lowest note — for instance, if another instrument (bass, piano) handles the bass note, or when you use multiple shapes of the same chord within a bar to make the accompaniment livelier.

This lesson doesn’t try to show every possibility. The construction of dominant 7th chords should be clear by now. The Chord Finder shows more V7 shapes; fiddling out others by yourself with the Analyzer is of course strictly allowed! This lesson is not intended for showing all possibilities. The construction of dominant seventh chords should be clear by now. The chord finder shows more V7 chord shapes; fiddling out others by yourself with the chord analyzer is of course strictly allowed!