Guitar Modes and Modal Scale Theory

Modal scales, sometimes called church modes, are the seven different ways the major scale can function in music. The major scale has seven notes and each one can be established as the root. Each root, or mode, has its own tonality and sound characteristics. Since all music is either based on or thought of in relation to the major scale, everything is in a mode. Understanding modes is critical to developing a knowledge of guitar theory. Modal scales have created an enormous amount of confusion, more than any other musical concept, and most of the available information about them is either incorrect or misleading.

Modal Scales Are Not Patterns
Modes aren't really separate scales and they certainly don't require learning separate patterns. Modes are based on the major scale and its patterns. In order to understand the theory behind modes, you must understand the major scale.

Major Scale Patterns
The notes of the major scale are scattered all over the fretboard. Trying to memorize the huge pattern as one unit is nearly impossible. The way to learn the whole scale pattern is to focus on small parts of it at a time. The most common way to do this is to break the large pattern up into 5 pieces. Once you memorize the individual pieces (a.k.a. positions or patterns) you can connect them and complete the whole fretboard. Even though each pattern is unique, they all are simply pieces of the entire unit. In other words, on their own the patterns don't become anything new. They are always major scale notes.

Chord Theory
The major scale can be played over any one of its notes or chords. For example, the G major scale can be played over a G major chord, Am, Bm, C, D, Em or F#mb5. When you play the G major scale over a G major chord the sound is the typical, happy major sound. This would require that you have a friend strum the G chord or perhaps you have a recording or looping device that can play back a rhythm track. You can play any part of the G major scale in any position or pattern. It doesn't even matter what note you start on. Just simply jump into the scale (anywhere you like) and play the notes (any order you like).

Now, play the G major scale over an Am chord. Again, this would require that you have a friend strum the Am chord or you use a recording or looping device that can play back a rhythm track. Suddenly, the sound changes. It's now dark and jazzy. You can play any part of the G major scale in any position or pattern. It doesn't even matter what note you start on. Just simply jump into the scale (anywhere you like) and play the notes (any order you like). 

Different Scale Modes
In the above example, why did the sound change? Because mixing notes and chords is exactly like mixing colors. Yellow and blue make green but red and blue make purple. Likewise, the G major scale over a G chord makes the so-called "Ionian Mode" sound while the G major scale over an Am chord makes the so-called "Dorian Mode" sound. So, it doesn't matter what kind of pattern or position you're actually playing the scale in nor does the note you start on mean anything. It all depends on what note or chord the scale is being mixed with.

Hear and Play Guitar Modes
In order to understand how colors change when mixed is something you have to see. Likewise, in order to understand what modes are you have to hear the sound of the scale change as you mix it with different chords. All the theoretical explanations in the world won't get the point across. You must play modes to hear them. Many music theory concepts have to be applied before you'll understand them and modal scales are no exception.

Greek Mode Names
Each scale note, or chord, has its own unique sound characteristics and identifying modal name. The seven Greek names, which have origins in the church, are Ionian Mode, Dorian Mode, Phrygian Mode, Lydian Mode, Mixolydian Mode, Aeolian Mode and Locrian Mode. The modal scale names are the same on the guitar as they are on every other instrument. This type of music theory is relative to all musicians.

How to Learn Modes
Modes spring from the understanding and application of other musical concepts. To learn modes, first learn the major scale and its patterns. Next, learn how the major scale is used to build chords. Finally, learn how these chords are used to make guitar chord progressions. With music, each concept supports the next. Don't try to get ahead of yourself by studying advanced theories that you're not prepared for.

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Mr. Desi Serna (Google me!)
http://www.Guitar-Music-Theory.com
Scales, Chords, Progressions, Modes and More