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. Each chord constructed from a scale plays a different role and knowing how they interact with each other will make you a better player and songwriter.
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.
The key signature can be any note, but for our example we’ll use the key of C. Since we’re in the key of C, we’ll use the C major scale:
The major scale is a diatonic scale which just means it has 7 scale steps. Therefore, in the 1st position of the scale all notes past the first 7 are just repeat notes. You can see them in the picture below in parenthisis.
Now if we have our key signature of C and the notes that we can play with the C major scale, how do we know what chords we can use? Keep reading!
Built In Chords
We can build a triad off of each scale step for a total of 7 chords. Start with the first note of the scale step and take out every other note until you have three notes to form a triad as in the picture below.
Constructing The 1st Triad
This is the triad we end up with:
Note: To show the triads in a form that you can play them in we have to often times move a note to the next string as in this case.
Constructing The 2nd Triad
Constructing The 3rd Triad
Constructing The 4th Triad
Constructing The 5th Triad
Constructing The 6th Triad
Constructing the 7th Triad
After we build all 7 triads, we know 7 chords that we can use in the key signature with no problems. Below are the 7 triads that we built (the 8th triad is the 1st triad repeating).
The names of the chords that these triads form are named:
1.) C Major
2.) D minor
3.) E minor
4.) F Major
5.) G Major
6.) A minor
7.) B dim