The Bebop Scale

                As we have discussed in past lessons, our Western musical system is based off of a seven letter musical alphabet.  This results in major and minor keys/scales that are composed of seven pitches.  In addition, even the modal scales are composed of seven pitches.  Pentatonic scales are only composed of five pitches, but they are based more on the concepts of Eastern and folk music. 

                When looking to compile a collection of pitches for musical improvisation, the music of bebop jazz era lends itself to a particular type of rhythmic feel and flow.  Most of this music is composed in a 4/4 shuffle feel that is complemented by flowing eighth note patterns.  A 4/4 measure can contain a maximum of 8 eighth notes, so an 8 pitch scale would be the optimal tool for musical improvisation in this musical style.

                The bebop scale is an eight pitch scale composed by introducing one addition chromatic pitch to a modal scale.  There are four types of bebop scales based on the four most common jazz seventh chords.  The four most common jazz seventh chords are the four chord qualities found in the diatonic seventh chords of the major and minor keys.  They are the major 7^th, minor 7^th, dominant 7^th and the half diminished 7^th chords.  This is demonstrated below by the included graphics that display the major and minor diatonic seventh chords.

                The bebop scale that is based off of the major 7^th chord is the called the major bebop scale.  A review of the modal scale relations to chords and improvisation reveals that the Ionian mode/scale is often used for improvisation over the major 7^th chord.  The major bebop scale is composed by adding a raised 5^th between the normal 5^th and 6^th of the Ionian scale.  The graphics below display both the formation of the major bebop scale and its written form in all 12 keys.

                The bebop scale that is based off of the dominant 7^th chord is the called the dominant bebop scale.  A review of the modal scale relations to chords and improvisation reveals that the Mixolydian mode/scale is often used for improvisation over the dominant 7^th chord.  The dominant bebop scale is composed by adding an interval that is a major 7^th from the root after the minor 7^th that is normally found in the Mixolydian scale.  The graphics below display both the formation of the dominant bebop scale and its written form in all 12 keys.

The bebop scale that is based off of the minor 7^th chord is the called the minor bebop scale.  A review of the modal scale relations to chords and improvisation reveals that the Dorian mode/scale is often used for improvisation over the major 7^th chord.  The minor bebop scale is composed by adding an interval that is a major 3^rd from the root between the minor 3^rd and the perfect 4^th that are normally found in the Dorian scale.  The graphics below display both the formation of the major bebop scale and its written form in all 12 keys.

The bebop scale that is based off of the half-diminished 7^th chord is the called the half-diminished bebop scale.  A review of the modal scale relations to chords and improvisation reveals that the Locrian mode/scale is often used for improvisation over the half-diminished 7^th chord.  The half-diminished bebop scale is composed by adding an interval that is a perfect 5^th from the root between the diminished 5^th and minor 6^th that are normally found in the Locrian scale.   The graphics below display both the formation of the major bebop scale and its written form in all 12 keys.

                In this Learning Music With Ray video I discuss the definition and composition of the bebop scale.  I cover a brief description of the overall concept of the bebop scale being an eight pitch scale, and why eight pitches are conducive to jazz improvisation.  I then go into a more detailed discussion on the four types of bebop scales and how they are derived.  Finally I cover tips on how to use these scales in musical improvisation.