Welcome to the latest installment of Chord by Chord, a series designed to build your understanding of harmony and the fretboard. Up to this point, I’ve taught you different triad (three-note chord) types—major, minor, and diminished—and how to find them on the fretboard. This time I’ll show you the fourth and last type of triad, augmented.
As you know, a major chord is built of three notes, the root, the third, and the fifth. An augmented chord shares two of these notes—the root and the third—but the fifth is raised a half step, making it augmented. Sometimes in notation an augmented chord is denoted with a plus (+) sign, but at AG we instead use the suffix aug next to the root note. Example 1 shows the notes in a C major chord (C E G) and Example 2 shows the notes in a Caug chord (C E G#). Sounds pretty different, right?
Example 3 demonstrates how you can build a Caug chord from an open C shape. Notice that we’re only changing one note in the chord—the fifth, which is on the third string. That’s what we’ll be doing in each one of these examples raising the fifth a half step, which just requires that you move a finger up by one fret. By the way, in both of the chords in Ex. 3, you could also include the open E string, but it’s easier not to, and you have the third (E) covered on the fourth string.
In Example 4a, the shapes are derived from a C major barre chord in third position. The Caug shape here is a bit awkward to finger, so just keep your eye on the ball—before you form the chord, look at the place where your fretting fingers will land and focus on how your hand will look when you get there. Example 4b is played on the top three strings. Notice that all you have to do here is move your first finger up a fret, because the fifth is on the first string.
The last two examples are derived from a C barre chord in eighth position. The first (Example 5a) is played on the bottom four strings, and the second (Example 5b) on the top four.
You should now know how an augmented triad is constructed and how to form Caug from different C major voicings. For some context, one song that uses a Caug chord is “All My Loving” by the Beatles. Next time we’ll work further on the augmented triad, focusing on Gaug.