We guitarists tend to learn chords by memorizing and recalling the physical shapes they form—little cells of dots that roam the fingerboard like constellations. Barres, diagonal lines, triangles, right angles, and even the Big Dipper are but a few of the shapes that emerge when we “connect the dots,” so to speak. But while this methodology certainly aids retention and recollection, it doesn’t account for how and why these sonic shapes actually exist. So how do chords get their shapes? Glad you asked!
Two-note harmonic intervals can certainly suggest chord sounds, but traditional chords require at least three notes. Theoretically, triads are three-note chords that can be spelled three different ways, from low to high. These are called inversions. The three spellings of a C major chord are root-3-5 (root position), 3-5-root ( first inversion), and 5-root-3 (second inversion). Each inversion is formed by transposing the lowest note up one octave, i.e., the bottom note of one inversion becomes the top note of the next one, played 8va.
Unlike guitarists, piano players learn all about chord inversions from the get go. Contrast this with your basic five-string, open C cowboy chord dissected in Fig. 1a—the first chord shape most of us learned—and you can see how all three inversions are lumped into one diagonal grip. Placing all three inversions on the same string group as shown in Fig. 1b reveals three “build- ing blocks” that can be used to form the basis for the other four common open major chord shapes depicted in Fig. 2 (A, G, E, and D), which, when transposed, are often referred to by the name of their open shape, regardless of the root—an “E”-shaped F# chord, “A”-shaped Bb chord, etc.
This is where the guitar and keyboard worlds divide. Guitar chord voicings, or spellings, are typically composed of three to six notes, one per string, and the physical layout of notes on the fingerboard makes it possible and often necessary to spread out notes, double them in different octaves, or to omit select chord tones. (Try inverting a Cmaj7 chord—root-3-5-7, 3-5-7-root, 5-7- root-3, and 7-root-3-5—and you’ll understand why.) The top and bottom brackets on each grid in Fig. 2 isolate numerous three- and four-note partial chords that reside within each full chord shape. Only the C and G shapes contain all three inversions in order, from low to high.
MAJOR & MINOR TRANSFERS
So here’s the deal: Any chord shape or voicing transferred to an adjacent string group will retain its intervallic formula, as long as notes on the B and E strings are adjusted as necessary to compensate for the guitar’s standard, asymmetrical tuning scheme, i.e., all notes transferred from the G to the B string must be raised one fret, and then stay at that fret when transferred to the high E string.
To illustrate, the 4x3 block of grids in Fig. 3 uses numbered scale steps to replace traditional dot markers and show root-position and first- and second-inversion major triads transferred across four adjacent three-string groups. Row 1 starts with G, the lowest-pitched root-position major triad available in standard tuning. As the chords move across adjacent string sets—from G to C to F to Bb—the roots remain on the same frets (as do the 3’s and 5’s in the first and second inversions), while the notes played on and above the B string are raised one fret, resulting in a transformation to the F and Bb shapes. The first-inversion major triads in row two begin with E (spelled G#-B-E), and transfer to A, G, and D as they move across each string set, while the series of second-inversion triads in row 3 starts on C (spelled G-C-E) moves to F, Bb, and Eb, respectively. Note the partial E-type, A-type, and D-type shapes used throughout. For homework, transpose each inversion up the same string set, as we did in Fig. 1a. Just move the first- and second-inversion shapes up the fretboard until each root coincides with the correct root note.
In Fig. 4, the 3 in each previous major shape is “flatted” (lowered a semitone, from the major third to the minor third) to produce the Gm, Cm, Fm, and Bbm root-position minor triads in Row 1, first-inversion Em, Am, Dm, and Gm triads in Row 2, and second-inversion Cm, Fm, Bbm, and Ebm triads in Row 3.
AUGMENTED AND DIMINISHED TRANSFERS
“Sharping” (raising) all of the 5’s transforms Fig 3’s major triads into the three rows of root-position (root-3-#5), first-inversion (3-#5-root), and second-inversion (#5-root-3) augmented triads diagrammed in Fig. 5. The lowest note in each inversion, be it the root, 3, or #5, again remains at the same fret when transferred across four string groups. Notice how, unlike major and minor triads, each augmented inversion maintains and the same shape as its root position. These are known as symmetrical inversions.
Similarly, flatting all of the 5’s turns Fig 3’s major triads into the root-position (root-b3-b5), first-inversion (b3-b5-root), and second-inversion (b5-root-b3) diminished triads transferred across four string sets in Fig. 6. The lowest available root-position diminished triad is Abdim, hence the chords in Row 1 are located a half-step higher than the previous major, minor, and augmented triads.
Moving on, Fig. 7 and Fig. 8 utilize the same transfer routine applied to suspended second and suspended fourth triads, respectively, and their inversions. Fig. 7’s root-position (root-2-5), first-inversion (2-5-root), and second-inversion (5-root-2) sus2 triads are formed by replacing the 3’s or b3’s in major or minor triad shapes with a 2 (a whole step above the root), while Fig. 8’s root-position (root-4- 5), first-inversion (4-5-root), and second-inversion (5-root-4) sus4 triads take shape by replacing the 3’s or b3’s in major or minor triads with a 4 (a whole step below the 5).
With four-note major seven (root-3-5-7), minor seven (root-b3- 5-b7), and dominant seven chords (root-3-5-b7), which have a root position, plus three inversions, it often becomes necessary to re-voice/re-spell traditional inversions to accommodate more playable shapes. Taking the 5 out of the picture—it’s the least important chord tone in any seventh chord—allows the reduction of a major seven chord to the three-note root-3-7 shapes transferred across four string groups in Row 1 of Fig. 9. Inverting these voicings gets pretty stretchy (though you are encouraged to explore them), so we’ll stick to string transfers for all of the remaining shapes. The first set of four-note root-5-7-3 voicings in Row 2 can be transferred across three adjacent string groups, but when we skip a string in the spelling of the chord, as in the pair of root-7-3-5 shapes in the last two grids, we run out of strings after just one transfer.
Fig. 10 presents three-note, root-b3-b7 minor seven shapes on four string sets in Row 1, and both four-note (root-5-b7-b3) and five-note (root-5-b7-b3-5[or b7]) shapes in Row 2. For homework, flat the 5’s in the four-note shapes to convert Gm7, Cm7, and Fm7 to Gm7b5, Cm7b5, and Fm7b5.
Two sets of three-note dominant seven shapes—root-3-b7 and root-5-b7—occupy Rows 1 and 2 of Fig. 11. The next two rows illustrate two sets of familiar looking four-note shapes played on three string groups—root-3-b7-root in Row 3, and root-5-b7-3 in Row 4. Row 5 brings a sharp nine to the dominant-seven party (the “Jimi Hendrix chord”), where it gets transferred over three string groups to form three shapes every guitarist should know. (Tip: Lowering all #9’s one fret forms ninth-chord shapes.) Row 6 takes the three-note voicings from Row 1 (starting on C7) and embellishes them with 5’s in the bass (5-root-3-b7) to produce three common shapes.
Finally, transferring the four-note Cmaj7, C7, and Cm7 voicings in Fig. 12 across three different string groups requires a bit of homework, as well as a shift in perspective. Here, we’re starting on the top four strings and working backwards, so you’ll need to lower any note that passes the second string by a half step.
Know your chord formulas, and you can embellish or alter any of the previous shapes to produce virtually any type of chord. For instance, lowering the 7 to the 6 transforms major seven chords into major sixes, and adding the 2/9 to dominant seven or minor seven shapes creates dominant nine and minor nine chords, respectively. The same goes for altered chords—just sharp or flat the 5’s and/or 9’s.
As you explore different chord types, keep an eye out for the many commonalities between shapes, such as G7 and Dbdim, Gsus2 and Dsus4, Am and C6, Fmaj7 and Dm9, G9 and Bm7b5, and so on. Transpose all shapes to all keys and positions, and you’ll never be more than one fret away from any chord you’ll ever need!