What exactly is a Scale?
A musical scale is an arrangement of a particular series of pitches. Most scales segment the distance between a given tone (pitch) and its octave into a.number of divisions. The keyboard illustration below presents the octave span from C to C.
In modern times this octave span is divided into twelve equal intervals known as semitones, which when taken together are called the chromatic scale.(play). (The word "chromatic" derives from the word meaning color. originally altered pitches in a mode were known as colored pitches and manuscripts often used a different color ink to notate them.) As you can hear, there is no real sense of completion at the end of the twelve notes of the chromatic scale; because the interval between each pitch is the same, any pitch could end the scale equally well.
Most music written after the Renaissance and before the twentieth century is based on a seven note subset of the twelve pitches of the chromatic scale; for instance: Do-Re-Mi-Fa-Sol-La-Ti-[Do]: the white pitches between C and C on the keyboard. This is called the diatonic Major Scale. (play) Like the hexachords of the Medieval period, all major scales share the same arrangement and relationship of individual pitches. What differs is the starting point. The chart below outlines the relationships between individual pitches in a major scale. Once again W stands for "whole-step" and H for "half-step"
A major scale can be built on any note and will always have the same arrangement of whole and half steps; the D Major Scale (D - E - F# - G - A - B - C# - D) shares the same pitch relationships as the C major scale. In this light, it may be better to think of the "major scale built on D" rather than the "D major scale."
When we say that a composition is "in C major" we mean that the piece is conceived in regard to a C major scale. It does not mean that the entire piece uses only the pitches of the C major scale. In most tonal music, there will be some sort of harmonic journey, in this case, beginning in a C major tonality, moving to some "far-off-point" tonally and then returning back to C.
The Minor Scale
The minor scale (play) is a different arrangement of whole and half steps. There are three forms of the minor scale, but for our purposes, the natural minor scale suffices.
The minor scale changes three pitches from the major scale: the third pitch (known as the mediant) is lowered a half-step as are the sixth (the submediant) and seventh (leading-tone) pitches. The other forms of the minor scale raise the sixth and seventh pitches back to where they would be in a major scale. Consequently, we can say that the heart of the minor scale is in the lowered third pitch.
The easiest way to remember these scales and relationships is that the pitch relationships that make up the major scale can be seen from C-C on the white keys of the piano, whereas the minor scale's pitch relationships can be seen from A-A on the white keys of the piano.
You can hear the difference between major and minor in listening to the same work rendered in a major key and a minor key. The example below is the children's song "Row, Row, Row" played first in a major key and then in a minor key.
Row, Row, Row Your Boat in Major then Minor
How do you tell the difference?
You need to listen, think about the characteristics and the feeling. You can also use the major-minor training environment created by Columbia University. Access it here.
The Scale is Hierarchical
A very important distinction between a scale and a mode is that scales imply hierarchies and relationships between individual pitches. The most important pitch of the scale is the first note, or tonic and all other pitches of the scale are understood in relationship to that pitch. The second most important pitch is the fifth note, or dominant; the third most important note is the fourth note, or subdominant. In the case of a C major scale, these roles are taken by the notes C, G, and F.
These hierarchical relationships take on an added importance when viewed from the perspective of tonality. If you recall, we said that a tonal piece begins in a home key; moves through other keys, reaching a "far-off point" before returning to a home key; and that these new keys are articulated by cadences. The way that a composer can create these cadences is by exploiting the hierarchical relation of the scale, through the use of chords built on these most important of pitches. The way a composer can demonstrate distance from a home base is by moving to more and more exotic keys.
All text © Todd Tarantino 2002-2012.
Not to be reprinted without permission.