In this lesson we’ll explore the basic forms of Bebop scales so you can start getting the patterns down and experiment with them in your music. There are times when you solo that you may want to do a scale run over a chord. Have you ever noticed that a straight descending scale run as eighth notes over a chord can sound a little off? Try playing a descending A Mixolydian scale over an A dominant 7 chord as straight eighth notes – the scale does not quite outline the chord the way your ear expects it to. This is due to the alignment of tones over strong and weak beats. Your ear really hones in on beats one and three in a four beat measure, these are the strong beats. Beats two and four are considered weak. Additionally anything that is a subdivision of a beat is considered weak. With the descending Mixolydian scale you have the following arrangement of tones-to-beat:
All of the chord tones end up on the “ands” of the beats. So how do we get descending runs to rhythmically align? We add chromatic passing tones and create “bop” scales. Play the descending scale again as eighth notes, but this time add a G#. Now look at how the beats line up:
Do you hear the difference in how the chord is defined? The chord tones end up on all the beats. Bebop scales were used sparingly in jazz during the 1930’s and really became popular in the 1940’s. There are different types of bop scales corresponding to the different modes, but they all have an added chromatic passing tone making them eight note scales.
Let’s start with the scale we just defined: Bebop Dominant Scale. The dominant bop scale is formed from the Mixolydian mode of the scale – the chromatic passing tone is added between the seventh and the root. Here is the C-Bebop Dominant scale:
This scale is normally played over V chords and II-V progressions. Try it out over a II-V-I progression, use the descending bop scale played as eighth notes starting on II and ending with the tonic on I. You’ll be amazed at how well it lays over the chord changes.
The next bop scale to consider is the Bebop Dorian Scale. In this scale we take the normal Dorian mode and add a chromatic passing tone between the third and fourth notes of the scale. The following figure shows the G-Dorian Bop scale.
This scale can also be used over II-V progressions and works well over the II chord. You’ll notice that we added the same chromatic passing tone in the G-Dorian Bop scale as we did in the C-Dominant Bop scale – the B natural. This is because G-Dorian and C-Dominant are both modes from the key of F major, so it makes sense that we would be adding the same chromatic passing tone. Unfortunately that rule does not apply for our next scale – the Major Bebop scale. In the Major Bop scale, built off the Ionian mode form, we add the chromatic passing tone between the fifth and sixth notes. Therefore an F Major Bop scale would look like the following:
The same chromatic passing tone is used in the Melodic Minor Bebop scale. Therefore the F Melodic Minor Bop scale would be:
Now that you’ve got the Bebop scale concept under your belt, along with four different bop scale forms, it’s time to listen for them in recordings and try them out in your own soloing!