A flute may be able to produce tones in its upper register that it cannot produce in its lower register. Generally, because of the way they are made, Native American flutes cannot produce tones 2 and 3 in the lower register, but may be able to produce them in the upper register. By the way, note the convention of giving both the first tone and its octave when setting out the tones of a scale. This convention lets us more easily see the relationships among all the tones. Notice how these criteria force the scale to be musical in the sense used above.
Pentatonic scales are the most widely used musical scales in the world.
They are found in China, Tibet, Mongolia, Oceania, India, Russia, and Africa, in the folk songs and hymns of Europe and the United States, and among Native Americans. A pattern of intervals is often called a mode . Every pentatonic scale must be in one or other of these five modes. Note that the assignment of numbers to these modes is arbitrary. On a Native American flute, the tonal center may or may not be the root tone.