absolute and relative systems
intervals
modes
chords
chord scales
fourths tuning for guitar
As I mentioned earlier, one of the best things about a relative system is the ability to transpose to any key while maintaining the pattern you already know. Even guitars in standard tuning can't do this because you have to negotiate around that annoying B string. This is the legacy of an instrument that was designed to strum open string chords. In this way, a standard tuning guitar is an instrument in the key of E in the same way a piano in an instrument in the key of C.
The Warr Guitar and other touchstyle instruments do not really have an open string tuning due to the fact that the first fret is usually occupied with an open string mute to prevent the open string from ringing when pulling off a note.
A modal scale consists of seven notes. Most people are familiar with what is commonly known as a major scale. If you play the white keys on a piano from C to C, you have just played a C Major scale. The scale is defined by which notes you play and which notes you leave out. A more specific method of defining the scale is by the intervals relative to each other. From C-D is a major second, two semi-tones or a whole step. From D to E is a whole step, from E to F is a half-step, and so on. Thus, a major scale could be described as 1 1 1/2 1 1 1 1/2.
Now, back to the keyboard. What happens when you play all the white keys on a piano, but instead of starting at C to C, you play from A to A. You're playing the same notes, but the tonal center is defined in the key of A, not C. Sounds different, right? The notes are the same, but the arrangement of the whole and half steps has shifted. Now the scale could be described as 1 1/2 1 1 1/2 1 1. This is commonly referred to as natural minor.
I use different names for major and minor because I picture them as two variations of a larger group of modes. I call them Ionian and Aeolian. There are seven natural modes that correspond to starting that very same scale on each scale degree. As we have already discussed from C to C is Ionian (major) and from A to A is Aeolian (minor) Here is a canonical listings of all the natural modes:
Of course, you don't have to play Aeolian from A-A on the white keys of a piano. You can start on any note, taking care to preserve the arrangement of whole and half steps. However, due to the absolute nature of note relationships on a keyboard, each new key represents a new pattern to learn.
On a Warr Guitar, once you learn a scalar pattern, you can transpose it anywhere without modification.
Another way of expressing the relationship of the modes is how they are modified relative to Ionian. Here they are arranged in progressions of how major or minor sounding they are:
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