Blues Scales

                As we discussed in the lesson on pentatonic scales, there are many differences between Western Music and other musical traditions.  One such difference was the development of equal temperament in order to balance out the tuning of keyboard instruments.  This Western tuning system does not account for the semitones used for melodic expression in other cultural styles of music.  Many of these diverse cultural styles played influential rolls in the creation of the American styles of spirituals, blues and jazz (which later led to the creation of gospel, rock and other styles).

                To account for this slightly bent pitch in melodic expression while being confined to an equal tempered scale, we created the concept of a blue note.  This concept allows the 3^rd, 5^th and 7^th intervals of the scale to be lowered by half a step.  Instruments that can play semitones often bend this note resulting in a pitch that is not perfectly accurate to the scale.  Fixed instruments such as the piano often slide between the lowered and regular versions of these pitches, allowing the two sounds to blend in the listener’s ear.

                The introduction of blue notes at the 3^rd, 5^th and 7^th intervals lead to the development of a blues scale which incorporated these pitches.  There are three versions of the blues scale which are based off of three different approaches to adding these blues notes.  The hexatonic blues scale is a six pitch blues scale.  In this version, people realized that the minor pentatonic scale already contained the desired b3 and b7 blue notes.  They merely added the b5 (or #4) to the scale to create a six pitched altered version of the minor pentatonic which contained all three blue notes.

                The heptatonic blues scale is an approach in which the major scale is altered.  In this approach, the 3^rd, 5^th and 7^th intervals of the major scale are lowered.  This results in a seven pitch scale that contains a minor third, diminished fifth and minor seventh. 

                The octatonic blues scale is an approach which also alters the major scale, but in a different way.  In this approach, the b3 and b7 are added to the seven pitches of the major scale.  This results in a nine pitch scale that contains both a minor and major third and seventh.  Quick sliding between these chromatic pitches is utilized to create the blue note inflection.  The b5 (or #4) is not used in this version of the scale.

                All three of these scale are used in blues and jazz (and other styles) composition and improvisation.  However, the pentatonic scale is a popular scale among improvising musicians (especially guitarists due to the way it lays on the neck of the guitar).  The ease of use and popularity of the pentatonic scale has caused the hexatonic blues scale to be the version that most people memorize and apply in their improvisation. 

                When improvising in the blues style, one can apply the hexatonic blues scale as a key signature over the entire 12 bar form.  As mentioned last week, the blues style allows for chromatic alterations that are not common in other styles of music.  For example, every chord within the form can be played as a dominant seventh chord (contrasting typical diatonic music where only the V chord is a dominant seventh chord).  This sonic nature of the blues style allows the hexatonic blues scale to be applied as a “one size fits all” improvisation scale.

                When using the blues scale for jazz and other forms of improvisation, it is often beneficial to apply more care.  Styles like rock and pop contain very little chromaticism.  Even in jazz, chromaticism is applied in a very different way (through V of V’s and temporary key centers – look at my lesson on connecting chord progressions).  Because of this, many people use the hexatonic blues scale applying both a minor and major tonality.

                In these applications, the hexatonic blues scale that we have been studying so far is considered to be a minor blues scale.  It is used to improvise over minor seventh chords since it contains many of the minor seventh chord tones.  When using this scale in this fashion, one should attempt to end phrases on the chord tones.  This brings a sense of closure to the melodic line.  The other pitches in the blues scale can be used as approach notes leading to the chord tones. 

                When improvising over dominant seventh chords, the minor blues scale is not always the best option. The minor third and diminished fifth (or augmented fourth) of this scale tend to clash too much with the major third and perfect fifth of the dominant seventh chord.  Of course this is a matter of taste since the dominant seventh chord does allow for increased dissonance.  However, in an attempt to stay true to the musical style being played (instead of straying too far into the blues style) people often use a major blues scale over this chord. 

                The rules between relative major and minor apply the same way when it comes to blues scales.  Therefore, a major blues scale will contain the same pitches as the minor blues scale three half steps below it.  For example, a C major blues scale will contain the same pitches as an A minor blues scale.  We are merely considering a different pitch to be the tonic within the sequence.  This creates a scale with a root, 2^nd, flat 3^rd, 3^rd, 5^th and 6^th.  The existence of the major third and perfect fifth in this scale cause it to be more consonant with the chord tones of the dominant seventh chord.  The flat third can be used as a quick slide or passing tone to create that blue note affect. 

                When improvising over a major seventh chord, the blues scale is not the best option.  Major seventh chords do not allow for the same level of dissonance as dominant (or even minor) seventh chords.  In these instances, use of the Ionian modal scale is still the best option.

                In this Learning Music With Ray video I discuss the definition and composition of blues scales.  I cover a brief description of the three types of blues scales and how their pitches relate to the scales we have already studied.  I then go into a more detailed discussion on the hexatonic blues scale in both its minor and major tonality.  Finally I cover tips on how to use these scales in both blues and jazz improvisation.  

                In this Learning Music With Ray video I discuss the definition and composition of blues scales.  I cover a brief description of the three types of blues scales and how their pitches relate to the scales we have already studied.  I then go into a more detailed discussion on the hexatonic blues scale in both its minor and major tonality.  Finally I cover tips on how to use these scales in both blues and jazz improvisation.