Introduction to Non-Diatonic Scales

In past chapters, we studied the diatonic scale and its modes. This week, we will expand our repertoire of scales to encompass some of the scales favored by composers in the late nineteenth and early twentieth century. As you’ll recall from music history class,many composers were influenced by the scales and tone colors of folk music; others were influenced by scales defined by the acoustical properties of sound itself.

Solfege – No Longer Always Necessary (!)

Some of the scales we will study fall into the pattern of diatonicism and therefore need to be spelled using their exact pitch classes (that is, according to the key signature of the relevant diatonic scale) when we notate them. In others, since diatonicism is irrelevant to them, can be spelled using any enharmonic spelling of the pitch class.

This means that not all of these scales can be sung using solfege. We will study systematic ways to practice singing without solfege, and discuss what makes them work.

5-Tone (Pentatonic) Scales

There are several types of pentatonic scales – the term simply means that there are five notes present. In Aural Skills IV, we will study the major pentatonic and minor pentatonic scales.

Major Pentatonic is composed from tones drawn from the diatonic scale, and as such, must be spelled using diatonic pitch classes. The solfege for the major pentatonic scale is do re mi sol la do. This scale’s ease of singing makes it universally accessible, and we can find it in folk music from all over the globe, from Asia to Africa to the Americas to Europe.

• The major pentatonic scale can be heard in many American classics such as Stephen Foster’s “Oh! Susanna.” You may also enjoy checking out Bobby McFerrin’s video on pentatonicism.

Minor Pentatonic is likewise composed from the diatonic scale, but corresponds to the Aeolian mode. The solfege for this scale is la do re mi sol la. (You’ll notice that it’s the same solfege as for the major pentatonic scale, but starts on la instead of do.)

• The minor pentatonic scale is also commonly used in folk music, such as in “What’cha Gonna Do” by Bela Fleck and Abigail Washburn.

6-Tone (Hexatonic) Scales

We will study two types of hexatonic scale.

The most famous hexatonic scale is the whole tone scale. It is constructed entirely from whole steps, and is therefore symmetrical. Some late nineteenth-century/early twentieth-century composers, most famously Claude Debussy (1862-1918) and Maurice Ravel (1875-1937), favored this scale in their compositions because it rejected the “hierarchy” of dominant-tonic harmony. Because there can be no dominant in whole-tone music, this gives it a quality of “weightlessness” that listeners identified with the blurred colors and brushstrokes of Impressionist painting (Claude Monet, Jean Renoir, etc.) Any enharmonic spelling is fine for this scale.

Another hexatonic scale, the augmented scale, may be less familiar to you. It is also known as the half-step minor third scale because it is composed of alternating half steps and minor thirds. Franz Liszt (1811-1886) used this scale to dramatic effect in his “Faust” Symphony. We call this scale the “augmented scale” because you’ll see it’s also composed of two interlocking augmented triads. Any enharmonic spelling is fine for this scale.

A New Heptatonic Scale (7-Tone)

In addition to the diatonic scale and its modes, we will study another heptatonic scale. The Lydian Dominant scale makes reference to the partials of the harmonic series. It is a feature of Tuvan throat singing, a folk music style in which singers project overtones above a fundamental pitch using their vocal technique, as we can hear in this week’s Spotify playlist. It is also used by some composers in Western classical music. Its solfege is do re mi fi sol la te do. Use exact spellings.

Octatonic Scales (8-Tone)

Octatonic scales are composed of alternating whole and half steps. Octatonicism is common in jazz, where the octatonic scale is also called the diminished scale. It is also common in many types of Eastern European folk music. It’s no accident that it appears extensively in the compositions of Igor Stravinsky, Béla Bartók, Dmitri Shostakovich, and Sergei Prokofiev.

The whole-half octatonic scale has a whole step between its two lowest pitches. Any enharmonic spelling is OK as long as the pitch class is correct.

The half-whole octatonic scale has a half step between its two lowest pitches. Any enharmonic spelling is OK as long as the pitch class is correct.

The Anatomy of the Octatonic Scale

The arpeggio of an octatonic scale is the fully diminished seventh chord. This is the case for both the types of octatonic scale that we will study in this class.

Intervallic Patterns Within the Octatonic Scale

The octatonic scale has inspired so many composers in so many different genres in part because of its fascinating intervallic qualities. Study the notes of the octatonic scales, and you’ll notice the following patterns:

• 4 pairs of half steps, separated by a whole step, i.e. (D, E-flat)-(F, G-flat), (A-flat, A), (B, C)
• 4 pairs of whole steps, separated by a whole step, i.e. (D, E), (F, G), (G-sharp, A-sharp), (B, C-sharp
• 4 minor thirds (which together build a diminished 7 chord)
• 4 major thirds
• 4 tritones