Most people might not realize it, but scales have their own built in chord systems. By using the notes from a scale we can make up 7 different chords. These chords made from the scale will work perfectly with the scale.
On this page you’ll see how it’s done using the A major scale.
In the tab below is the notes from the A major scale. There are only 7 different notes in the scale, but we’ll repeat the notes some at a higher octave (it makes building the chords easier).
We can decode the chord system of a scale by building triads. Triads are simply 3 notes that make up a chord (“tri” means 3, like in tricycle). To build one we take every other note of a scale until we have three.
So, for example, to build the first chord we start with the first note of the scale (an A note), skip the 2nd note (B), add the 3 notes (C#), skip the 4th note, and then add the 5th note to the chord (an E). Therefore our first triad that we can build from the scale is A, C#, and E. These are the notes that make up the A major chord, so the first chord in the A major key is A major. We continue to do this with every note of the scale . The A major scale has 7 different notes, so we can extract 7 chords built off of each of the notes.
If we continue up the scale and create all 7 triads, these are the chords we end up with:
1.) A Major
2.) B minor
3.) C#/Db minor
4.) D Major
5.) E Major
6.) F#/Gb minor
7.) G#/Ab dim.
You can write a song in A major using these chords and each and every chord will “fit” in the songs. That’s not to say that you can’t use “outside” chords if you wish, but harmonically these 7 chords naturally come with the key of A major.
Each chord construted from a scale plays a different role and knowing how they interact with each other will make you a better songwriter. The 1st, 4th and 5th chords that are built from a scale are the most used chords in popular music and should be the most important chords in your song in A major. The minor chords are frequently used in bridges, but can be used anywhere in the song.
You can use the triads built from a scale to create a chord progressions and use the scale itself to create the melody.
At first, you may find it easier to begin with the chord progression and create the melody last, or you may not choose to create the melody on your guitar at all. Some people will opt to sing the melody.
Here is a sample progression built from the A major scale/chord
system on this page.
A – D – F#/Gbm – E – A