Triads & Chord Character

Chord Character

To the ear, pure Major and Minor chords are easy to distinguish from one another. Basically, Major chords sound happy and Minor chords sound sad. Diminished, Augmented, 6th, 7th, 9th, 11th and 13th chords all contain dissonant tones that make them sound oddly incomplete or discordant. The 6th, 9th, 11th and 13th chords have an additional note added to the basic triad and are most often used in Jazz.

Triads

A triad is a group of 3 notes that are a third apart. It is this numeric relationship that defines the triad. The chart below illustrates notes that are a third apart using red and white text. On the standard 5 line musical staff, triads are even easier to recognize. Major, Minor, Diminished and Augmented chords can all be formed using triads.

Music Notation

What do the Arabic numbers in 6th, 7th, 9th etc. mean when describing chords like A7, G6 or C add 9? It means you’re adding the 6th, 7th or 9th etc. tone of that chord‘s scale to the triad that makes up that chord. The numbers correspond to the added notes’ position relative to the first note of the scale. The chart below shows how numbers correspond to notes in a scale. Notice that the scale goes on after the octave (original note is repeated) and the numbers continue. Theoretically the notes and numbering continue infinitely.

The Roman numerals represent the triads (chords) that begin on the letter names relative to the first chord in the key. Capital Roman Numerals represent Major chords, lower case Roman numerals represent Minor chords. For example, a vi chord in the key of C Major (below) is A minor (A-C-E). A V chord in the key of C Major (below) is G major (G-B-D). A III chord in the key of A minor (below) is C Major (C-E-G).

The chart below uses the keys of C Major and A Minor because there are no sharps or flats in either key, which helps simplify the illustration.

* Althought the triad at the VII position in a Pure Minor scale actually forms a Major Chord (See Above: G B D), tradition dictates that the chord formed at the 7th position use the leading tone from the Harmonic Minor, which then creates a Dinimished Chord (G# B D).