Earlier posts (#173, #179, and #191) look at how to form -- and play -- different permutations (or "modes") of a key.
And these principles apply to any key -- including the key of A, as we'll explore here. For example, when you take the 7 notes of the A major scale -- A, B, C#, D, E, F#, G#, A -- you create 7 modes starting on each respective note.
Because each mode begins and ends on a different note (or "tonic"), each pattern is a distinct sound. In this example, the tonic of A Ionian is A ... while the tonic of B Dorian is B ... and so on.
Each sequence of notes sounds nice. But they sound especially good (and full) when played as chords. For example, if you play the A major scale (a.k.a., the first mode, A Ionian) as a sequence of chords, you get:
The A Ionian mode sounds good fleshed out as harmonies because it's essentially the major scale on steriods. And just like the notes, these same 7 chords can also be arranged into 7 permutations -- like these three patterns, for example:
And the same idea applies to all of the other chords in this key, as you can see here....