Grade Six Music Theory Harmony Lesson 2: Triads and Chords

Chords

A chord is any group of notes which are played at the same time. 

Chords can have any number of notes in them, as long as there is more than one! 

Chords can have any combination of notes in them, but our ears usually prefer listening to chords which are built to the rules of harmony, rather than just a random selection of notes.

These chords are built according to the rules of "tonal harmony". (Don't worry about the names of the chords for now!)

 

Whereas these chords were created by my cat walking across my piano keyboard (he's never studied harmony).

As we just saw, chords built using the rules of tonal harmony have names. There are a few different methods we can use to describe chords in words, and we'll take a look at these shortly. Before that, we'll go back to the basics of how to build chords in tonal harmony - using TRIADS.

Triads

A triad is a 3-note chord. Take a note (call it the "root"), add a third and a fifth above it, and you have created a triad. (All triads are chords, but not all chords are triads.)

Take a note: We'll take an F:

Add a major third above it:

or a minor third:

Add a fifth above it to make a major triad:

or a minor triad:

We can also build a triad with a minor 3rd and a diminished 5th, like this:

This is called a diminished triad.

Scales and Triads

Each scale has a group of triads whose roots are each degree of the scale. Here's the scale of C major, in triads:

Look at each degree of the major scale and see if it produces a major, minor or diminished triad.

This pattern is the same for all major keys.

Let's do the same with a minor scale - We normally use the harmonic (not melodic) variety of the scale to work out triads in music theory. But in practice, triads from the melodic scale will also be common. Here's the group of triads which exist in A minor:

 Watch out! Chord 3 is an augmented triad- rarely used in practice. However, you may also see a major chord III (e.g. C major in this case) and also a major chord VII (G major in this case) – because these two chords are the same as the relative major key tonic (C major) and dominant (G major).

Naming Triads

Here are three methods we can use to name triads:

1. We can use the letter name of the root of the triad, and then add either "major", "minor" or "diminished" (or "augmented") to it.

E.g. C major (or just "C" for short), E minor (or "Em") and B diminished ("B dim").

2. We can use Roman numerals. Each degree of the scale gets a Roman numeral. We use capitals for major, small letters for minor, and a small circle ° for diminished. (Augmented chords have a + sign, but we don't use them in grade 6.)

Major Scales:

Minor Scales:

3. We can use the technical name of the degree of the scale, plus major/minor/diminished as needed.

The Roman numeral system is the most useful, because it lets us understand the triad in relation to the key of the music, and it's a nice, short way of writing triads. Make sure you learn the Roman numerals!

Naming Chords

Triads are very "theoretical" things - we use them a lot when we analyse music, but we don't see them so often in practice. Triads only have 3 notes, but in real life, chords usually have more than 3 notes. Very often they have 4 notes, but can have many more.

The most simple kind of 4-note chord is a triad with the root repeated in a higher octave. (Sometimes the third or fifth of the triad is repeated instead of the root.)

The triad of C major:

The chord of C major:

Chords which contain only the notes which already exist in the triad use the same naming systems as triads, so this is C major, or I (in the key of C major).

Another kind of 4-note chord is one which has a note added which doesn't exist in the triad, for example this one:

Here we've got a G major triad, with an F at the top. F is an interval of a 7th above the root, G, so we call this chord G7, or V7 (in C major). Or we can use the technical name of "dominant seventh" (in C major). Dominant seventh chords are extremely common. You've probably come across lots of them in your music making, but in fact for grade six music theory, you only need to be able to recognise them - you don't have to actually write any ! :)

• Prev
• Next