BY KATE KOENIG
Welcome to the latest installment of Chord by Chord, a series designed to build your understanding of harmony and the fretboard. In the last lesson, we went over the E7 chord. This time we’ll continue with dominant sevenths, this time working on B7.
If you’ve been following along, you know that a dominant seventh chord is a major triad plus a flatted seventh. Example 1 shows the notes in a B major triad—B, D#, and F#—and Example 2 depicts a B7 chord (B D# F# A).
For two ways of getting to a B7 chord from a B barre chord in second position, see Examples 3a–b. Note that Ex. 3a is an open voicing and Ex. 3b a barre shape. Example 4 shows how to get to a B7 voicing on the top four strings, with the fifth (F#) in the bass. You might have noticed that this B7 shape is the same as the open A7 you learned earlier, but moved up two frets.
Example 5 demonstrates how to make a B7 barre chord in the seventh position. Again, this shape is moveable—shift it down two frets for A7 and another two frets for G7, etc. Moving up the neck, Example 6 shows how to get to a B7 voicing in ninth position.
You should now know how to form B7 in a variety of ways on the fretboard. One song that makes good use of this chord is “Folsom Prison Blues” by Johnny Cash. (Note that Cash uses a capo at the first fret, so the chord sounds as C7.) Next time we’ll further explore the dominant seventh chord.