The blues is often the first improvisational vehicle introduced to the novice jazz improviser, and rightfully so, as it is the most common song form found in jazz. However, it is often presented to beginning improvisers in an overly-simplified way that fails to acknowledge many of the harmonic and melodic conventions that became "standard practice" of the bebop practitioners. These two posts aim to shed some light on many of these "blues conventions" that the jazz musician is expected to know, and will hopefully better prepare the developing improviser to playing a blues with more experienced jazz musicians.
Misleading Presentation of the Blues in Jazz
The blues is presented to beginners in a variety of ways depending on the literature and teacher. However, two features are almost always present in the way the blues is taught to the beginning jazz improviser:
It is a 12-bar form consisting of the I, IV, and V chords.
You can improvise over it using the blues scale.
Although these things are definitely true, they should each be followed by a big "but":
Throughout the bebop and post-bebop periods, the blues form in jazz developed into a highly-evolved musical form capable of countless harmonic variations. Many of these harmonic variations have become the standard and "default" ways to play the blues in a jazz context. To say that the blues merely consists of the I, IV, and V chords is a gross and misleading over-simplification.
Although the blues scale is an effective device to employ over the blues, it does not acknowledge the above-mentioned "standard and default harmonic variations" used over the blues form. In order to navigate these variations, the developing improviser must understand how to target guide tones and implement effective voiceleading.
The Ornamentation of the Blues
So what are these harmonic variations that bebop musicians made the "standard and default" ways to play a jazz blues? It all boils down to using ii-V progressions to set-up the major points of the blues form. The example below illustrates a more-or-less standard 3-chord blues progression using the I, IV, & V chords in the key of Bb.
If we think of this form as consisting of three 4-bar phrases, we see that each phrase starts on a different one of the I, IV, & V chords. Phrase one starts on the I chord, phrase two on the IV chord, and phrase three on the V chord. The key to understanding the harmonic variations to a jazz blues is seeing how the added chords are simply ii-V progressions that lead into each phrase.
The example above illustrates a basic "jazz blues" progression. As it can be seen, the chords that have been added are ii-V progressions that lead into the new chord of each phrase. Here's a quick breakdown:
In bar 4 we prepare the transition to the IV chord by preceding it with a ii-V. The tricky thing to remember here is that since our I chord in a blues is a dominant-quality chord, it is therefore already acting as V of the IV chord in bar 5. So, we simply smooth-out that transition by preceding it with the corresponding ii of the IV chord. Make sense?
In bar 8 we're preparing the transition to the ii chord in bar 9. However, before I explain that, I should really explain why we're going to a ii chord in bar 9 instead of a V chord... The goal of bars 9 & 10 in a 3-chord blues progression (the first example) is to lead back to the I chord in bar 11. Being as the ii-V progression is the most common way of tonicizing a chord in the jazz idiom, in a jazz blues, a ii-V progression is used to tonicize bar 11 instead of a V-IV progression. Therefore, in bar 8 of a jazz blues, we're preparing the transition to ii-V with a ii-V of ii (D-7 -> G7 is ii-V of C-7). Kinda confusing, I know, but if you re-read those last few sentences while looking at the examples, it will all make sense eventually. (Maybe my next post should be about functionally analyzing chord progressions!).
In bar 11, we're resolving to the I chord and using a G7 to prepare the ii chord in bar 12 (G7 is V of C-7).
In bar 12, we're using a ii-V progression to prepare the transition back to the top of the form.
So what does all this information and analysis mean to us as jazz improvisers? Basically, it means we need to be comfortable inserting and navigating ii-V progressions in the blues form.
Using ii-Vs in the Blues
For a basic treatment of the ii-V progression in jazz, refer here and here to my earlier posts on the topic. The first post deals with navigating ii-Vs using diatonic scale material and 7-3 resolutions. The second post deals with navigating secondary dominants using chromatic notes and the harmonic minor scale. Each of these posts are highly relevant to improvising over a blues, and be sure to pay special attention to the post on secondary dominants. In the above example, the G7 is functioning as a secondary dominant, and it's difficult to capture the sound of that chord without using intervals found in the harmonic minor scale.
If you feel comfortable with all the concepts discussed in the above-mentioned posts, try implementing some of those ideas in the bars bars 4, 8, & 9-12 of a jazz blues. I like to call those bars the "make-or-break" bars of a jazz blues progression, because the stuff you play over those bars is largely going to determine how "jazzy" your solo sounds.
To demonstrate the importance of these "make-or-break" bars, the example below uses basic blues scale vocabulary in bars 1-3 & 5-7, and basic ii-V vocabulary in bars 4, 8, & 9-12.
As you can hear, even though half the solo is made up of ideas from the blues scale, the accurate and clear execution of ii-V vocabulary in the "make-or-break" bars of the progression gives the solo an authentic and "jazzy" bebop sound.
So where can you go from here? Here are a few practice suggestions:
Practice inserting the proper ii-Vs into the "make-or-break" bars of the blues. Be sure to practice and memorize this progression in all 12 keys.
Practice navigating the inserted ii-Vs with basic ii-V vocabulary. For maximum clarity, focus on the 7-3 resolution.
Practice using the Phrygian Dominant scale over the V/ii chord in bars 8 & 11.
Practice targeting guide tones and connecting them through the progression. (A guide tone is a harmonically significant note that helps define the motion of a chord progression.) The following example illustrates a possible guide tone line through a blues in Bb:
In the second part of this post, I'll discuss strategies for approaching bars 1-3 & 5-7. Stay tuned by signing-up for my mailing list!