Most of the melodies I use for beginners are built on the pentatonic scale, partly because this limits the notes students need to worry about (some pentatonic fiddle tunes use only 2 fingers!), and because there are so many great tunes that use the pentatonic scale.
In classical music, this scale was hardly used in baroque times and then became more popular in Romantic and impressionistic music. In traditional music, the pentatonic scale has been very common for centuries in Celtic music, American folk, gospels, blues, country, rock, jazz, East European, West African, Chinese, Mongolian, Japanese, Greek, Native American, Southeast Asian, South American, Afro-Caribbean — in fact, it’s hard to find places where the pentatonic scale is not in common use.
Carl Orff believed the pentatonic scale was natural for children, so the Orff method focuses on its use for younger learners. It’s also common in the Kodaly method, and in Waldorf schools, for similar reasons.
Below are a few examples of common uses of the pentatonic. It’s easy to visualize the 5 notes of this scale when you see it on a piano: if you play just the black keys, you have a major pentatonic by starting with the 3 black keys, and then playing the other two — the 1, 2, 3, 5, 6 notes of the scale. The minor scale starts two notes lower, just as any relative minor does, and results in the 1, 3, 4, 5, 7 notes of the scale. This is the foundation of blues and rock music.
I find it important for students to learn full scales, in order to understand in mind, ears, and hands, the feeling of a diatonic scale using all the letters from A-G, and all the fingerings. However, pentatonic scales are used in lots of good melodies, and make these tunes easy to learn, because by going over this limited scale, the student can recognize a pentatonic pattern as a scale in its own right, and not just a scale that’s missing some notes. This means the student has about 30% fewer notes to shop for when hunting for notes! Their ears will have that much better chance to guide the fingers, and to recall the melody later.
Whether in Celtic, jazz, rock, blues, bluegrass, or many other styles, the pentatonic scale is a great learning tool, and a versatile improvisatory pattern to explore.