The third: happy or sad

It comes down to one note

A basic chord is three notes: a root, a third and a fifth. The root names the chord. The fifth is stable and says almost nothing about mood, which Grade 1 explained through the overtone series.

The third carries the feeling. Move it one fret and the chord flips from bright to dark.

Hear the one fret difference

Same root, same fifth. Only the middle note moves, by one fret. Play them back to back a few times.

Play both, then play them again in the other order.

Why is it called a third?

Count up the scale from the root. In A major that is A, B, C sharp. The third note of the scale, so it gets called the third. This is the numbering you met in Grade 3, used for a distance instead of a position.

Major means the wider version, four frets above the root. Minor means the narrower one, three frets. All chord naming works like this. A number tells you which note, a word tells you how wide.

This is why m7, maj7 and 7 are not arbitrary letters. You are reading a recipe, and Grade 5 is where you learn to cook from it.

The two thirds, measured

Counting in frets from the root. One fret is the entire difference between a bright chord and a dark one.

Three frets from the root gives the minor third. Four gives the major. The fifth sits seven frets up either way, which is why it says nothing about mood.

Listen. Is this chord major or minor?

And this one?

Build an A minor chord: find A, C and E

Root, minor third, fifth. Labels are hidden, so use the shapes from Grade 1.

A and E are both open strings. C is three frets above A on the A string.

Match each chord part to what it does

Tap something on the left, then tap what it pairs with.

Takeaways

• Root, third and fifth make a basic chord.
• The third decides major or minor, and the two sit one fret apart.
• Three frets from the root is minor, four is major.
• Chord names are recipes. A number says which note, a word says how wide.