TRIADS are the simplest “true” chord form (as opposed to DYADS like 3rds, 4ths and 5ths) and the one that you absolutely have to understand inside out in order to build more advanced chords. Triads are built by taking the 1, 3 and 5 notes starting from any scale degree and playing them together. Which means that every MAJOR scale will have 3 MAJOR triads, 3 minor triads and 1 diminished triad.
The following 4 triad types are built from stacked MAJOR and minor 3rds.
Revisit the section on INTERVALS if they’re still confusing for you.
Triads are easy to construct but can sometimes confuse people when they see the numbers 1, 3, 5. They automatically assume that the triad can only be created from the TONIC (1), MEDIANT (3) and DOMINANT (5) scale degrees – not true.
Like all other chord types, a triad occurs whenever the proper INTERVAL pattern is met. It really doesn’t matter what the root note is. If the pattern fits – it’s a triad. You should also be aware that chords created from stacked 3rds are often referred to as ‘tertian’ chords.
A MAJOR triad is constructed from a ROOT note, a MAJOR 3rd (M3) and a minor 3rd (m3). Learn this one well!
In the above, the distance from C to E, F to A and G to B are all 4 half-tone intervals (M3), and the distance from the ROOT note to the last note in each is a Perfect 5th (P5) thus making them the PRIMARY MAJOR TRIADS for the C MAJOR scale. Now, you can obviously use different combinations of 3rds to create other triads, but they are considered “auxilliary” or “secondary” and aren’t as common.
For the C MAJOR scale above, the MAJOR TRIADS are:
- C – e – G
- F – a – C
- G – b – d
A C minor triad is the same as the C MAJOR triad with a flattened iii scale degree which pushes it into a different KEY. In this case, the obvious choice would be C MAJOR’S parallel KEY – c minor.
The C diminished TRIAD is the same as the C minor TRIAD with a flattened V scale degree.
An AUGMENTED TRIAD is the same as a MAJOR TRIAD with a sharpened V scale degree.
The thing to take away from this section are the INTERVAL patterns necessary to create the various TRIADS. You stick to them and you’ll always be right – no matter the KEY.