Introduction to Modes

MODES ARE EASY, when you understand them! I personally had a difficult time with modes and spent many hours reading every book I could find on them, but all I got was more confused. Now I understand how they are used, they seem so simple... so what I want to do is to try and explain all the things that confused me, and hope that it helps you.
MODES ARE THE SAME AS THE MAJOR SCALE, but have a different tonal centre. What does that mean, and why is it important? Well to understand that you need to understand a bit about Diatonic Chord Sequences, which will be covered in a lesson by itself. What you need to understand for now is that all the modes have the same notes as a major scale, but you would play it over a chord other than the root. huh? If play a G Major Scale over an A minor chord, you would be playing the A Dorian Mode. Don't try and understand that just yet, just grasp that idea. Using the modes is as easy as playing the Major Scale, just the tonal centre (or chord that you are playing over) does not have the same tonal centre as the Major Scale.
So lets get to grips with a few terms that you will need to understand first:
Diatonic Chord Sequence - This explains the chords found in a key. For example: The diatonic chord sequence in the key of C is, C, Dmin, Emin, F, G, Amin, Bdim. More in this in couple of lessons time.
Tonal Centre - This is the foundation of the harmony, usually the chord that the mode will be played over. This will also help define what I call the "Home Notes" which are the notes that you can settle on and sound good. It's really important that you get to grips with this idea and I will give you some examples of how to use this later.
Parent Major Scale (PMS) - This is my term for the Major scale that a Mode comes from. The notes of the mode and the PMS will be the same but the tonal centre will be different. For example, I might write B Dorian mode (PMS: A Major) which will mean that the PMS of B Dorian is the A Major Scale.
Home Notes - These notes will help you define the tonal centre and are usually the chord tones of the Tonal Centre.
Series - Looking at the series of modes that come from one Major Scale. For example, the modes that all come from the same PMS: in C Major would be C Ionian, D Dorian, E Phrygian, etc.
Parallel - Looking at all the modes that have the same tonal centre. For example, The modes that have the tonal centre of C (but different PMS) would be C Ionian, C Dorian, C Phrygian, etc.