Triads on Guitar, All Over the Neck
Three notes, three strings, and the whole neck opens up.
A triad is the smallest chord there is: three notes, a root, a third and a fifth. The third decides everything — a major third makes it major, a minor third makes it minor — and the fifth is the same in both. Every open chord you know is a triad with some of its notes doubled to fill six strings; take the doubling away and what is left is small enough to play anywhere on the neck, in a dozen places, without a barre.
That is why triads are the thing guitarists mean when they say they want to "know the neck". Here is C major, every note of it, everywhere on the guitar. The figure follows the text.
Three notes, everywhere
The dots above are the whole chord: every C, E and G on the neck. Any three of them close enough for one hand make a C major triad — the big shapes are just particular choices of five or six of them. Tap a note to hear it; change the root to see the same pattern shifted, because a triad, like everything else on the guitar, is a shape before it is a set of note names.
Five big shapes, then the small ones
The five open-chord forms, moved up the neck, are where most players start — the CAGED shapes, each a triad with its notes doubled across the strings. They are landmarks. But a barre chord is a handful, and it cannot move quickly. Drop the doubled notes and each big shape has a small one inside it: three or four strings, one note each, that says the same chord in a quarter of the space. Those are what rhythm players actually play above the fifth fret.
On three strings
The triad lesson everyone eventually gets is this one. Take the top three strings only. C major has exactly three ways to sit on them, and they walk up the neck in order: G on the bottom at the nut, then C on the bottom at the third fret, then E on the bottom at the eighth, then G again at the twelfth, an octave up. Root position, first inversion, second inversion — the same three notes with a different one lowest, and between them they cover the whole neck on three strings.
Then the same on the next three strings down, and the next. ‹ › in the figure walks every one of them; the inversions page is about why the order of the notes matters. What matters here is simpler: three strings, three shapes, and you can play any major triad anywhere within a fret or two of where your hand already is.
Minor is one note lower
Lower the third and every shape above becomes minor: the same three-string grips with one finger moved back a fret. Learn the major set and you have learned the minor set; the difference is which note you bend down.
The triads of a key
A key has seven notes and, stacked in thirds, seven triads — the chords that songs in that key are made of. In C major they are C, D minor, E minor, F, G, A minor and B diminished. The figure shows each one inside the scale it comes from, so you can see that the chord tones are the scale with four of its notes left out — and that the next chord is one step over, not somewhere else.
This is the view that makes progressions make sense on the neck. A I–vi–IV–V — C, Am, F, G — is four small shapes within reach of one position, not four barre chords in four places.
What NoSheet does with this
The app's harmony games are exactly this page, by ear. A chord sounds; you hear which degree it is; you find its shape with the root shown — first the triads of a key in order, then any triad on any root, then the inversions. The shapes are never memorised as pictures: you build them from the root and the degrees, which is why they come out the same on a ukulele or a piano. Build Shapes is the browser version, no microphone — the chord sounds, the root lights, and you find the shape before it is revealed.
Learn the three-string triads because they are useful. Then learn to hear them, because that is when they stop being shapes and start being music.
Questions
- What is a triad on guitar?
- A three-note chord — a root, a third and a fifth — played with one note per string on three strings. Every open chord is a triad with some notes doubled; the small three-string shapes are the same chord without the doubling.
- How many triad shapes are there on guitar?
- For one chord on one set of three adjacent strings, three: root position, first inversion and second inversion, which repeat every twelve frets. Across the four three-string sets that is twelve shapes for any major or minor triad.
- Should I learn triads or CAGED first?
- Learn a couple of CAGED shapes to play songs, then the three-string triads on the top strings. CAGED gives you landmarks; triads give you something you can move and hear. The app teaches the small shapes by building them from the root and degrees.
- How do I practise triads by ear?
- Play a chord, then find its shape before you look — the app's Build Shapes game does this: a chord sounds, its root lights up on the neck, and you find the triad. The browser version on this site does the same without a microphone.