The two scales that we will explore, given to the right in the key of A, are the major and minor pentatonic scales. Each of these scales has a European counterpart and exists as a "gapped" version of existing scales. A "gapped" scale is identical to an existing scale but is missing notes found in that other scale.
For the major pentatonic scale, the notes are identical to the natural major scale but the 4th and 7th notes are omitted. The spelling of the A major scale is A-B-C#-D-E-F#-G#-A, but that for the major pentatonic form is A-B-C#-E-F#-A. An ornamental note is added between the 2nd and 3rd notes, and this note (C natural in score) is called the "flat 3rd." It exists as one of the defining notes of the minor pentatonic scale but may be incorporated in the major pentatonic scale to very positive effect. The pattern, then, becomes A-B-C-C#-E-F#-A.
In the minor pentatonic scale, the 2nd and 6th notes are missing from a natural minor scale. The A natural minor scale is A-B-C-D-E-F-G-A. The spelling of the minor pentatonic form is A-C-D-E-G-A. In addition, an ornamental note, the "flat 5th," is added so that the pattern is A-C-D-D# or E flat (depending on direction)-G-A. This ornamental note is actually a critical blue note. This last form is sometimes called the "blues scale."
It is critical to learn the fingerings for these scales in arrangements in which no open strings are used. This permits the scales to be moved to any key just by shifting positions. There are five positions for each and every scale type including scales other than the pentatonic scales.
As critical is to learn the functions of each note by number, since this will permit the improviser to find the notes in any position without having to figure out the name of every note within every key, though the player should also develop this familiarity. The functions follow and are based on the scales given in the illustration:
A (Tonic) B (2nd) C (flatted 3rd ornament) C# (3rd) E (5th) F# (6th)
A (Tonic) C (flatted 3rd) D (4th) D# or E flat (# 4th or flatted 5th) E (5th) G (flatted 7th)
Knowing the function of each note in each scale is critical to theoretical conversations, hearing events within the music, correct resolution (addressed in later article) and use within a key, and finding the way around the instrument.
These scales are the stuff of American popular music as it emerged in the 19th century. The major pentatonic scale most likely has its origins in British folk music, especially that of Scotland, and it made its way to America first aboard the ships that transported English colonists and then, in the nineteenth century, aboard British ships that carried goods to America.
The major pentatonic scale is found in a considerable number of American folk songs, many of which we learn growing up. The scale was used to create new songs, but as often British folk songs were fitted with new words to reflect the immediate concerns of the lives of the users. "Shenandoah," which uses the major pentatonic scale, likely started as a sea chanty but is known to Americans with a very different text than the origin and with a text that makes no reference whatsoever to the sea or maritime life!
The major pentatonic scale also found widespread use in the Spiritual as black worshipers abandoned the stock hymns taught them by evangelists and began to form a body of worship music that reflected their lives and beliefs. Major-key Spirituals were encouraged by slave owners fearing that songs in minor could evoke feelings of hopelessness and depression, in other words, of opening the door to the mood of "nothing to lose" and the actual physical dangers that could result.
In application, the major pentatonic scale is essentially a major scale, and that means the direction or "push" of the music is upward. This is a critical point to remember when using it to improvise and with regard to blue note resolutions. In addition, in folk songs, the major pentatonic scale was often colored by the borrowing of the minor or "flat third" of the minor pentatonic scale, usually at the end of a stanza of music, where is is often still found today. In Froggy Went a Courtin', the scale used is the major pentatonic, but the flatted third, the C natural note, of the minor pentatonic scale is inflected in the second measure of the third line.
The minor pentatonic scale likely began in the minor-key "sorrow song" Spiritual. Minor-key Spirituals are not found in great quantities relatively speaking, and most did not come into currency until after the Emancipation. Exemplified on the video is the sorrow song Motherless Child. Pictured at the end of the video are the slave auctions, the possible impetus for the lyrics.
At first the sorrow song remained in minor, then later the minor pentatonic scale jumped tonality and began to be applied over chords in major keys. This is exemplified in the urban blues of Muddy Waters. The video, which one of Waters' urban blues songs and presents it as a guitar duet, demonstrates an adherence to the minor pentatonic scale in the melodies, both the primary melody, the "call," and the response in the second guitar, the "answer."
Again, the minor pentatonic scale is a gapped natural minor scale. Critical to remember in improvising, and especially in resolving blue notes, is that the direction of the minor pentatonic scale is downward.
Here, then, is the basic language of blues, that is, a mixture of two scales with different pitches and directional pull. If one combines the two scales, one gets C-D-E flat-E-F-F#-G-G-B-C, all of the notes in the twelve-note chromatic scale except the flatted second, the flatted 6th, and the natural 7th! That all these notes are available does not mean that they can be used in any combination, and here is where the difficulty lies in learning to play blues.
The impact of the scales upon the blues chords and rhythmic aspects of playing blues will be the focus of the next two articles. How to make all the elements work together will be addressed in the last in this series of articles.
Finally, when you learn these scales, do not use open strings. If you used only closed positions (notes that are fingered) you will be able to move the scales to any key simply by shifting positions on the neck. There are five possible fingerings for every scale, and they lay out end to end in consecutively higher block positions.