Guitar/Scale Theory

From Wikibooks, the open-content textbooks collection

Around the 11th century Western music began to become standardized. Music around this period was created using the "Church Modes" which took their names from the tribes of ancient Greece. These early modes formed the basis for Gregorian chant and the secular music of the medieval period. As instruments and forms evolved, some of the Church Modes became redundant as musicians found that those modes did not suffice for their musical needs. A few of the Church Modes went on to form the basis of our "major-minor" system and it is from these modes that Baroque musicians created the harmonic theory that has dominated music right up to the twentieth century. The Ionian mode is now called the Major scale. The keyboard layout became standardized on instruments in the 15th century, it was tuned to play the C major scale. By the time the piano was invented in the 17th century, the C major scale had become the firm foundation on which all teaching of music theory is built upon or related to.

Since the piano keyboard has been such a dominating force in music, particularly in the Classical period from the 17th to the early 20th century, a complete study of scales must make some reference to it. Thus, to begin any understanding of scale theory, it is best to first look at the piano keyboard, and then compare it to the guitar fretboard.

[edit] The Piano Keyboard

Before you begin it is good idea to familiarise yourself with the notes of the C major scale. Note that it is the convention to use roman numerals to label scale degrees

A piano keyboard showing the C major scale. Note that all the notes of the C major scale are on the white keys.

If you played each key up the keyboard, you would play the 12 tone chromatic scale, which means that you are playing all the notes available. The keyboard on a piano is setup for that when you play the C major scale, you only use the white keys. This is because the C major scale uses no sharps (#'s)or flats (b's), which would be played on black keys.

It is important to recognize that the distance between two adjacent white keys is not always the same. For example, between the C and D keys is a black key which plays an intermediate semitone, but between E and F keys there is no black key (That is because E does not have a sharp form, and thus F does not have a flat form. This is also the case in notes B,C). If you count the number of keys between each note in the C major scale, the pattern would be 2-2-1-2-2-2-1. This pattern of tones and semitones is the most fundamental pattern in Western music, as all of the modes are derived from it.

In general, the piano enables a player to press any combination of keys and produce any number of chords. However, unless you always play in the key of C, you have to remember the correct combination of white and black keys to play a particular chord or scale. In contrast, on the guitar each fret is a semitone higher than the previous fret, so if a player memorizes the pattern of notes that plays a C major scale, they can move this pattern (or scale shape) to a different position and be playing a different major scale.

[edit] Structure of the Major Scale

The major scale (or Ionian mode) is one of the diatonic scales. It is made up of seven distinct notes, plus an eighth which duplicates the first an octave higher. In solfeggio (a system where each note is sung using a syllable) these notes correspond to the syllables "Do, Re, Mi, Fa, Sol, La, Ti, (Do)". The simplest major scale to write or play on the piano is C major, the only major scale not to require sharps or flats, using only the white keys on the piano keyboard. The intervalic pattern for any major scale is 2-2-1-2-2-2-1, meaning that the difference from the first note to the second is 2 frets, from the second to the third is 1 fret, etc. The difference in notes can also be called steps, 2 notes being a whole step, and 1 note being a half step. This pattern in steps can be shown as W-W-H-W-W-W-H.

Major scale in the key of C

C - D - E - F - G - A - B - C

Two Octaves Of C Major:

C major two octaves ascending at the seventh position

This shape is moveable, and the fingering is shown below

e:---x---|---x---|-------|-------|
B:-------|---x---|-------|---x---|
G:---x---|-------|---x---|---x---|
D:---x---|-------|---x---|---x---|
A:---x---|---x---|-------|---x---|
E:-------|---x---|-------|---x---|

[edit] Structure of the Minor scale

[edit] Natural minor

The natural minor scale (or Aeolian mode) is another one of the diatonic scales. A natural minor scale can be created on any key using the formula W-H-W-W-H-W-W.

Minor scale in the key of C

C - D - Eb - F - G - Ab - Bb - C

Two Octaves Of C Minor:

C natural minor two octaves ascending at the seventh position

This shape is moveable, and the fingering is shown below

e:-------|---x---|-------|-------|-------|
B:-------|---x---|---x---|-------|---x---|
G:---x---|---x---|-------|---x---|-------|
D:-------|---x---|-------|---x---|-------|
A:-------|---x---|-------|---x---|---x---|
E:-------|---x---|-------|---x---|---x---|