Shell Voicings on Guitar
Root, third, seventh — the fifth can go.
A seventh chord has four notes, and on a guitar four notes are one more than you usually need. Drop the fifth and what remains — the root, the third and the seventh — is a shell voicing: three notes, two or three fingers, and everything that makes the chord what it is. The third says major or minor; the seventh says major seventh or dominant. The fifth says nothing that the bass player and your ear don't already know.
Shells are the chords of jazz rhythm guitar, the Freddie Green sound, and the fastest way to play through a chart without a barre in sight. Here is Cmaj7 as a shell. The figure follows the text.
The three shells you need
There are three kinds of seventh chord that matter first: major seventh, minor seventh and dominant seventh. Each has a shell with the root on the A string and another with the root on the E string. Six grips, and you can play every chord in most jazz standards.
Root on the A string
Cmaj7: root at the third fret, the third on the D string, the major seventh on the G string. Cm7: the third and the seventh both a fret lower. C7: the major third back up, the seventh stays flat. Three chords under one hand at one fret, and the only thing that moves is a finger or two.
Root on the E string
The same three with the root on the low E: Cmaj7 at the eighth fret, Cm7, C7. Between the two root strings you can play any seventh chord within a couple of frets of wherever you are.
One finger moves
Play Cmaj7, then C7, then Cm7, all at the third fret. The seventh drops a fret, then the third does. That is a chord changing quality with almost no movement — the whole point of shells, and the reason a ii–V–I can be played with one hand barely leaving the spot: Dm7, G7, Cmaj7.
Where the fifth went
Nowhere you'll miss it. The fifth is the note the ear supplies for free — it is the strongest overtone of the root, and it is the note a bass player is most likely to be holding. Leaving it out makes the chord lighter and the change between chords smaller. When you want it back, the full shapes have it; when you want the chord to move, the shell wins.
Beyond the shell
A shell is also the frame you add colour to. The note on the string above the seventh is a ninth or a thirteenth waiting to happen; the shape stays and the extension sits on top. That is a page of its own, but the shells are where it starts — and where the chord shape game starts too, once the sevenths join it: hear the chord, know the quality from its third and seventh, find the shell with the root shown.
Questions
- What is a shell voicing?
- A seventh chord with the fifth left out: just the root, the third and the seventh. The third and seventh are the notes that make the chord major, minor or dominant, so the shell keeps the chord's identity with three notes and two or three fingers.
- Why drop the fifth?
- The fifth adds nothing to the chord's quality, the ear supplies it from the root's overtones, and a bass player is usually holding it. Without it the chord is lighter and moves to the next chord with less hand movement.
- Which shell voicings should I learn first?
- Maj7, m7 and 7 with the root on the A string, then the same three with the root on the E string. Six grips cover most jazz standards.
- Are shell voicings only for jazz?
- They come from jazz rhythm guitar, but they work anywhere a full chord is too thick: playing with a keyboard, comping under a singer, or moving fast through changes.