Guitar Pentatonic Scale
The pentatonic scale is one of the most widely recognized scales in music throughout the world. Popular in music in both the east and the west, it is truly a ubiquitous scale in its usage. (Interestingly, it was developed independently in cultures throughout the world.) The literal meaning of pentatonic is simply 5 notes. So, in a real sense, any scale that is a repeating sequence of 5 notes can be categorized as a pentatonic scale, in contrast to a heptatonic scale (7 notes) like the major or natural minor scales. There are many variations of 5-note scales, from the ‘Coltrane’ pentatonic (R,M2,m3,P5,M6) widely used in jazz improvisation to the ancient Japanese ‘Miyako-bushi’ scale (R,m2,P4,p5,m6).
The two most common forms in Western music are called the major pentatonic and the minor pentatonic scales. The major pentatonic scale consists of the notes R,M2,M3,P5,M6. It basically eliminates the scale degrees of P4 and M7 from the major scale. The minor pentatonic consists of the tones R,m3,P4,P5,m7. It eliminates the tones M2 and m6 from the natural minor scale (Aeolian mode).
The major pentatonic is commonly used in major chord progressions. It is used in all styles of music, probably being the most commonly used scale in the world, and it is often heard in pop, rock, country, jazz, and reggae music. Innumerable songs have been written using the major pentatonic scale. Some examples are Amazing Grace (Newton), Oh! Suzanna (Foster), and the opening bassline of My Girl (The Temptations).
The minor pentatonic is also used in almost every style of music in the world and is commonly heard in blues, jazz, hard rock, and country. It is commonly used over minor chord progressions. However, it is also an unusual scale in that it can be placed, and is often heard, superimposed in harmonic contexts where the scalar intervals don’t actually fit the underlying chord progressions. Improvisors commonly use the minor pentatonic over major progressions in both rock and jazz music. For instance, in a progression of E major to A major, one would typically use the E major pentatonic (E,F#,G#,B,C#) to improvise. However, rock, blues, and jazz players will often shift into E minor pentatonic (E,G,A,B,D) for a time to create tension. The notes G and D are both ‘wrong’ in the harmonic context, but this scale has been so commonly used in this context that the listener considers it normative.
It is also common for this scale to be used over a dominant 7th chord (R,M3,P5,m7). Again, though the G natural note is ‘incorrect,’ it is so commonly used over this chord that to most listeners it seems to be the ‘correct’ scale, even though the dominant pentatonic (R,M3,P4,P5,m7) would be the more technically ‘correct’ scale to use. So in this sense, the minor pentatonic has become the more ‘correct’ or normative scale in actual usage. (Note that most improvisors when using a minor pentatonic over a dominant 7th chord often slightly bend the 3rd upward toward the M3 sound–typically about a quarter tone. Hear early Eric Clapton for excellent examples of this.)
The minor pentatonic is the 5th mode of the major pentatonic. Both scales are identical in the pitches but merely differ either in root note or determination from the underlying progression. The C major pentatonic is C,D,E,G,A. The Am pentatonic is A,C,D,E,G. If you are improvising, the determination of the scale is by the underlying harmonic context. That is, if you are playing the notes of the pentatonic A,C,D,E,G over the progression C Major, F Major, and G Major, it would be considered the C major pentatonic. If those same notes were used over the progression Am, Dm, and Em, it would be considered the Am pentatonic. The same notes are used but with a different harmonic context–in the same way that all 7 modes are formed out of a base major scale and are determined by the underlying harmony, the same notes can be called by different names (i.e., C major pentatonic or Am pentatonic) based on the chord progression underlying it.
Mastery of this scale is ESSENTIAL for any improvisor. It is the single most important scale to master for improvisation. Since there are only 5 modes of this scale, there are, naturally, 5 positions or patterns (or boxes in some idioms) to learn. This is the ‘home base’ starting point for learning to improvise. And in certain musical genres, such as the blues, this scale is not just the most essential scale but could also be argued to be the only necessary scale. Though other scales are important to learn and help the improvisor to sound more sophisticated, one could make a career in the blues using just this scale, and many have proved this out in their careers as ‘bluesmen.’
Remember that it is not just knowing the scale shape or ‘box’ that matters, it is being able to improvise with it, by learning melodic phrases (‘lines’) and patterns (‘licks’).