46
Chapter VI. Scales and Key Signatures
Exploring Theory with Practica Musica

VI. Scales and Key Signatures

Scale Degrees

Each of the seven notes of a major or minor scale has a name. These names will be convenient when describing scales and later will be used in harmony, too, so this is a good moment to learn them.

The first note of any scale is the tonic. Next in ascending order come the supertonic, mediant, subdominant, dominant, submediant, and subtonic. The logic behind these names is clear if you view a scale with its tonic in the center:

Figure 2. Two Scales

Suggested Practica Musica Activity: Hearing Scale Degrees. Identify which degree of the scale is played.

The three most important notes of the scale are the tonic, the dominant, and the subdominant, which for historical and acoustical reasons form something like foundation posts for the scale: the dominant is a fifth above the tonic; the subdominant a fifth below. The mediant, the third degree of the scale, gets its name from being halfway between the tonic and the dominant; in a sense it mediates between them. The submediant mediates between the tonic and the subdominant. Finally there's the supertonic, just above the tonic, and the subtonic, just below it. When the subtonic is only a half step from the tonic, as in a major scale, it can also be called the leading tone because it seems to lead back to the tonic.

The Natural Minor Scale

The major scale discussed in chapter 2 has a close relation in the natural minor. The same white key pattern used for the major scale produces the natural minor if you begin with A instead of C. Put another way, you can sing a natural minor scale with the familiar solmization syllables by beginning with La instead of Do: La, Ti, Do, Re, Mi, Fa, Sol, La. The natural minor scale can be expressed as the following pattern of whole and half steps: W H W W H W W, as in the ladder in figure 2.