Diatonic mode

For your convenience (or if you are not that familiar with the different types of chords and how they sound), the chord track starts off in "diatonic" mode (unless you are using a more exotic key/scale that does not permit this).

Without delving too deeply into music theory, it is enough to know that the seven diatonic chords form the harmonic foundation of Western music, providing the basis for creating progressions and harmonies that sound cohesive within the key. You will notice that you can construct most popular chord progressions with just those seven chords. The 7th variants of the diatonic chords (e.g. using one note extra) are also available for some different "flavouring".

Diatonic playing is only available if the used scale comprises seven notes (e.g. is "heptatonic").