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 previous lessons we’ve covered D7, G7, and C7 chords. This time we’ll go over another dominant seventh, A7.
Remember that there are different types of seventh chords, and the dominant seventh is the one most commonly used in popular music. Often referred to simply as a seventh chord, this variety is just a major triad with the addition of the flatted seventh. So, an A major triad is spelled A C# E (Example 1) and an A7 chord is A C# E G (Example 2). Notice how much of a difference in character the addition of that one note makes.
Examples 3a–3b show two different ways of making A7 from an open A chord. To get to A7 from an A major barre chord in fifth position, try Example 4. This A7 is moveable, meaning that you can play its shape at any spot on the fretboard—for instance, move it down two frets for a G7 chord or up two frets for B7. To make some A7 voicings higher up the neck, see Examples 5–6.
Now you should know a variety of ways to form A7 on the fretboard. A good example of a song that uses A7 is Pink Floyd’s “Breathe.” In the next lesson we’ll continue exploring dominant seventh chords, focusing on E7.