Understanding Basic Music Theory - Catherine Schmidt-Jones [59]
Pentatonic Scales
In Western music, there are twelve pitches within each octave. (The thirteenth note starts the next octave.) But in a tonal piece of music only seven of these notes, the seven notes of a major or minor scale, are used often.
In a pentatonic scale, only five of the possible pitches within an octave are used. (So the scale will repeat starting at the sixth tone.) The most familiar pentatonic scales are used in much of the music of eastern Asia. You may be familiar with the scale in Figure 4.67 as the scale that is produced when you play all the "black keys" on a piano keyboard.
Figure 4.67. A Familiar Pentatonic Scale
This is the pentatonic scale you get when you play the "black keys" on a piano.
Listen to the black key pentatonic scale. Like other scales, this pentatonic scale is transposable; you can move the entire scale up or down by a half step or a major third or any interval you like. The scale will sound higher or lower, but other than that it will sound the same, because the pattern of intervals between the notes (half steps, whole steps, and minor thirds) is the same. (For more on intervals, see Half Steps and Whole Steps and Interval. For more on patterns of intervals within scales, see Major Scales and Minor Scales.) Now listen to a transposed pentatonic scale.
Figure 4.68. Transposed Pentatonic Scale
This is simply a transposition of the scale in Figure 4.67
But this is not the only possible type of pentatonic scale. Any scale that uses only five notes within one octave is a pentatonic scale. The following pentatonic scale, for example, is not simply another transposition of the "black key" pentatonic scale; the pattern of intervals between the notes is different. Listen to this different pentatonic scale.
Figure 4.69. Different Pentatonic Scale
This pentatonic scale is not a transposed version of Figure 4.67.It has a different set of intervals.
The point here is that music based on the pentatonic scale in Figure 4.67 will sound very different from music based on the pentatonic scale in Figure 4.69, because the relationships between the notes are different, much as music in a minor key is noticeably different from music in a major key. So there are quite a few different possible pentatonic scales that will produce a recognizably "unique sound", and many of these possible five-note scales have been named and used in various music traditions around the world.
Exercise 4.8.3. (Go to Solution)
To get a feeling for the concepts in this section, try composing some short pieces using the pentatonic scales given in Figure 4.67 and in Figure 4.69. You may use more than one octave of each scale, but use only one scale for each piece. As you are composing, listen for how the constraints of using only those five notes, with those pitch relationships, affect your music. See if you can play your Figure 4.67 composition in a different key, for example, using the scale in Figure 4.68.
Dividing the Octave, More or Less
Any scale will list a certain number of notes within an octave. For major and minor scales, there are seven notes; for pentatonic, five; for a chromatic scale, twelve. Although some divisions are more common than others, any division can be imagined, and many are used in different musical traditions around the world. For example, the classical music of India recognizes twenty-two different possible pitches within an octave; each raga uses five, six, or seven of these possible pitches. (Please see Indian Classical Music: Tuning and Ragas for more on this.) And there are some traditions in Africa that use six or eight notes within an octave. Listen to one possible eight-tone, or octatonic scale.
Figure 4.70. An Octatonic Scale
Many Non-Western traditions, besides using different scales, also use different tuning systems; the intervals in the scales may involve quarter tones (a half of a half step), for example, or other intervals we don't use. Even trying to write them in common notation can be a bit misleading.