Strum an open G and your fingers are spread across six strings — but you’re only playing three different notes. A G major chord is built from three notes: G, B, and D. Everything else on those six strings is one of those three, repeated higher or lower.
That’s the whole chord. Once you can see those three notes — where they come from and where they sit under your fingers — the shape stops being something you memorized off a chart and becomes something you understand. And that understanding is what lets you change it, move it, and recognize it inside other chords.
The teal dot is B — the third, the note that makes it major.
The three notes, string by string
Here’s what’s actually sounding when you strum that open G shape (the standard three-finger version, frets 3 2 0 0 0 3 from the low string up):
| String | Fret | Note | Job in the chord |
|---|---|---|---|
| 6th (low E) | 3rd | G | root |
| 5th (A) | 2nd | B | third |
| 4th (D) | open | D | fifth |
| 3rd (G) | open | G | root |
| 2nd (B) | open | B | third |
| 1st (high E) | 3rd | G | root |
Read down that note column: G, B, D, G, B, G. Three unique notes, some repeated. The G shows up three times, the B twice, the D once — and that’s normal. A guitar has six strings but a basic chord only needs three different notes, so the shape just doubles some of them up to fill out the sound.
Where G, B, and D come from
Those three notes aren’t random. They’re pulled straight out of the G major scale, which runs:
G – A – B – C – D – E – F#
To build the chord, you take the 1st note, skip one, take the 3rd, skip one, take the 5th:
- G — the 1st note (the root)
- B — the 3rd note (the third)
- D — the 5th note (the fifth)
That 1–3–5 pattern isn’t special to G. It’s how every major chord is built — pick any major scale, take the 1st, 3rd, and 5th, and you’ve got that chord. Learn the pattern once and you can find the notes in any major chord without looking them up.
Why these three sound right together
Each of the three notes has a different job, and that’s what makes the chord feel complete:
- The root (G) tells your ear what the chord is. It’s home base — the note everything else is measured against.
- The fifth (D) is the most agreeable note in music. It reinforces the root without adding any color of its own, which is why it makes the chord sound solid and full.
- The third (B) is the one doing the emotional work. It’s the note that decides whether the chord is happy or sad — major or minor. Lower that B by a single fret to B♭ and your bright G major turns into a dark G minor. Nothing else moves.
That’s why the third gets the teal dot in the diagram. The G and the D build the foundation; the B is what gives the chord its feeling.
The common G shapes — and what changes
You’ll run into several versions of G. They’re all still built from G, B, and D — they just double up different notes or add one. Here’s what’s actually different:
| Shape | Frets (low→high) | What’s different |
|---|---|---|
| Easy / “cowboy” G | 3 2 0 0 0 3 | The standard three-finger shape above |
| Big “rock” G | 3 2 0 0 3 3 | Swaps the open B (2nd string) for a D — fuller, heavier sound |
| G/B (slash chord) | x 2 0 0 0 3 | Same notes, but B is now the lowest — great for a descending bass line |
| Gmaj7 | 3 2 0 0 0 2 | Adds an F# on top — a softer, jazzier cousin, no longer plain G major |
Notice the first three are all still just G, B, and D in different arrangements. Only the Gmaj7 adds a genuinely new note (F#, the 7th) — which is why it gets its own name.
Moving G major up the neck
The open shape isn’t the only G. Because a chord is defined by its notes, not its position, you can play G anywhere those three notes line up. The most common movable version is the E-shape barre at the 3rd fret (3 5 5 4 3 3) — the same shape as an open E chord, slid up so the root lands on G. Same three notes, G-B-D, higher up the neck. Once you see chords as notes rather than fixed pictures, the whole fretboard opens up — which is the heart of triads and building chords.
What about the “A/G” slash chord?
People often search “a g chord” and mean one of two different things. Usually it’s just a G chord — the G major you’ve been reading about. But sometimes it’s a slash chord like A/G, which is a different animal: that means an A major chord (A–C#–E) with a G note in the bass underneath. The slash always means “this chord, with that note on the bottom.” So A/G isn’t a type of G chord at all — it’s an A chord sitting on a G bass note. Worth knowing, so the two don’t get tangled.
Common questions
What are the notes in a G major chord?
G, B, and D. The G is the root, B is the third, and D is the fifth. In an open shape you play those three notes across six strings, so G and B get repeated.
Why is it called G major and not just G?
“Major” describes the kind of third inside it. A G major chord uses a major third (B). Lower that note to B♭ and you’d have G minor — same root, very different feeling. When people just say “G,” they almost always mean G major.
How do I build a G chord from the scale?
Take the G major scale (G A B C D E F#) and pull out the 1st, 3rd, and 5th notes: G, B, D. That 1–3–5 recipe builds the major chord in any key.
Why does my G chord use six strings if it’s only three notes?
Because the guitar has six strings and a triad only needs three notes, the shape doubles some up. The open G plays G three times, B twice, and D once — repeating notes fills out the sound without changing the chord.
Is the big four-finger G better than the easy one?
Neither is “better” — the four-finger version (3 2 0 0 3 3) swaps the third on top for another D, giving a fuller, more driving sound that suits rock and strumming. The easy three-finger shape is lighter and quicker to grab. Use whichever fits the song.
Go deeper
You just saw the whole logic behind one chord — three notes, one simple rule. Here’s what almost no one shows you: the same rule quietly runs every chord, every key, and every pattern on the neck. The day it clicks, the fretboard stops being something you memorize and starts being something you read. The free 3 Theory Secrets videos are where it clicks.
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