The Diatonic Scale
The foundation of Western tonal harmony
A diatonic scale is a seven-note scale composed of five whole steps and two half steps. The major scale is the most common diatonic scale. Any chords built using only the notes of this scale are called "diatonic chords."
Chords in a Major Key
I
Major
Ex: C Maj
ii
Minor
Ex: D min
iii
Minor
Ex: E min
IV
Major
Ex: F Maj
V
Major
Ex: G Maj
vi
Minor
Ex: A min
vii°
Diminished
Ex: B dim
Why is this important?
Understanding the diatonic scale allows you to know which chords "belong" in a key. This is crucial for songwriting, improvisation, and analyzing music. 90% of pop, rock, and country songs use almost exclusively diatonic chords.