You may have noticed in the last four sections (major scales, natural minor scales, harmonic minor scales, and melodic minor scales) that the scales each had 7 notes. In many cases scales are comprised of 7 notes, but this is not universal. Some scales, such as the pentatonic scales have fewer than 7 notes, and some scales have more than 7 notes.
The pentatonic scale is comprised of W-W-minor third-W where W is a whole or a major second. The minor third is between the E and the G in the example above. One thing you’ll notice is that there are no half steps in the pentatonic scale. These 5 notes comprise the C pentatonic scale. Keep in mind that the major scale can begin on any key. For example we can begin on the key of F.
If you have a keyboard handy, play these examples and notice the slight oriental sound. If you are interested in the oriental scale, you can learn about it at *Scales: Oriental Scales. The exotic sound comes from the minor third incorporated into the scale. Most western scales don’t have the minor third. I want to show one more example, the G pentatonic scale.
The example starting on G has the same form as the above two scales and is brought up to illustrate that within every major scale, there are three pentatonic scales beginning on the tonic (C), the subdominant (F), and the dominant (G).
As a composer, this allows you to create melodies in the major scale using three different pentatonic scales. This is great to add variation to your melodies. You can add the slight oriental sound in the midst of a western style melody to grab the attention of the audience and make your piece more memorable.
The pentatonic scale may appear simple and restrictive for the composer by limiting him/her to 5 notes. However, the limitations can benefit the composer by helping him to create a melody; there aren’t as many options/notes as with other scales. Also, the pentatonic scale can be incorporated into the major scales giving the composer another tool to vary his/her melody.