# 7 A broader understanding of pitch systems

So far, you have focused on the notes and intervals of the Western gamut and how these are represented with the help of staff notation. This is in keeping with one of the overall goals of this suite of courses: teaching the basics of Western music theory and staff notation. In the remaining sections of this course, you will look at how pitch is organised and represented in other musical traditions. As will become apparent, Western music theory does not even begin to account for the diverse range of musics in the world. Nevertheless, certain broad similarities are shared by many of these musics, including the existence of pitch systems and intervals. This section and those that follow consider the number of pitches in various pitch systems, then the intervals between those pitches, and finally the stability of those pitches and intervals.

There are many pitch systems beyond the 7- and 12-note ones you have studied so far. For example, the Aka people from the Central African Republic and the Republic of the Congo (see Figure 9) make use of a pentatonic (5-note) pitch system.

Figure 9 Map showing the Central African Republic and the Republic of the Congo (to be distinguished from the Democratic Republic of the Congo to the south and east of it)

The piece in Video 3 is an Aka lullaby called Mo boma sung by two girls (Arom, 1978, p. 30). The performers sing distinct but complementary melodies that together present the five notes of the pentatonic pitch system. (Traditional Aka music is polyphonic, meaning that two or more distinct melodies are sung simultaneously).

## Activity 9

Allow around 5 minutes

Listen to Mo boma and try to make out the notes that comprise the pentatonic pitch system.

Video 3 Mo boma (make sure to open the link in a new tab/window)

If you listen closely, you may be able to hear that there are six distinct notes in play. However, the lowest one stands in an octave relationship with the highest one, so the system is a pentatonic one overall.

OpenLearn - Introduction to music theory 2: pitch and notation
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