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  • The Pool Principle

    The ability to improvise effectively over the ii-V7-I progression has long been a hallmark event for musicians studying jazz. In fact, one would be hard pressed to find a jazz standard or song from the Great American Song book that does not include at least one of these tried and true sequences. 

    As an improviser and educator, I do my best with students to relate playing over different sequences, chord qualities, etc, to something visual and often times, unrelated to music. This is especially true when discussing how to negotiate the ii-V7-I progression. 

    How many of you have been to the swimming pool before? My guess is that most of you have; if you have not, you’re missing out! At many pools there is a diving board and as I thought about how to relate playing over the ii-V7-I to my students, I thought about the sequence of diving from the board into the water. At first, these two things seem completely unrelated, but with a little bit of imagination, I’ve found my students have found the following concept immensely helpful in their ability to play over this progression. 

    To fully understand how this concept works, it’s first important to identify some common problems that students encounter when attempting to integrate vocabulary over this sequence. Often, I find the sheer number of options in terms of what to play over each chord, can be overwhelming; especially when a young student is first attempting to play over the sequence. Repetition is our friend and so that brings us to the first part of the “pool principle”. 

    Enter the “diving board”. Barring some seismic event, a diving board will always stay in its place; cemented firmly in the ground. For me, this is representative of the material I have my students play over the “ii-“ chord. As diagramed below, you can see that the harmonic information is a mixture of a D-7 arpeggio and scale steps that are all diatonic to D dorian minor with the exception of the tone Gb, which is a chromatic passing tone to where it’s headed, which is F natural on the downbeat of measure two. The information is effective both in the fact that it clearly outlines the harmonic shape of the chord and it also conveniently sets up the next chord in the progression via the chromatic passing tone on the upbeat of beat 4.

    Just as there are three parts to the ii-V7-I sequence, there are three parts to a diving sequence. Having already made our way down the board, it’s time for us to make the “jump”, or to play over the “V7” chord. If we look to history as any indication, the V7 chord is where we as improvisers can get away with a lot of things harmonically, provided our ears are trained well enough to make a strong resolution that ties the line together. In any scenario, when you “jump” into the water, no matter how many times you run from the board, your jump will always be slightly different than the time previous. What this translates to me harmonically is simply how safe or daring we choose to be as improvisers. Looking at figure 1a below, you can see that the information over G7 is again a mixture of scale steps and skips and it remains entirely diatonic to the key. Similarly, in figure 1b the shape of the line remains the same yet the harmonic information deviates slightly to allow for some non-diatonic tones to be introduced which create some harmonic tension. Perhaps the “jump” for figure 1b was a belly-flop! Along those lines, what would a cannonball sound like? What would an acrobatic flip sound like? 

    The only remaining part of our harmonic journey is the destination; better known as the I chord. For our visual, this brings us to the water. Again, all things being equal, the water in the pool is more or less going to be the same. Thus, the way we resolve our ideas from the “jump” to the “water” will be to resolve to basic chord tones; specifically, the Root, 3rd and 5th as diagrammed by figures 1c, 1d, and 1e below. Notice that the harmonic information over the “ii” chord as well as the “I” chord is very much the same in each of these examples. What changes each time through is which notes gets played over the V7 chord as well as the slight change in resolution depending upon whether the line is headed towards the Root, 3rd or 5th of the I chord. 

    An everlasting characteristic about improvising is imagination. As an educator, I’m passionate about connecting students to visualizations that go beyond the notes and rhythm and engage the brain in synthesis of the information from different perspectives. 

    I’ve found that in addition to using this visualization to teach how to play over the standard ii-V7-I progression, it has worked wonders when implying tried and true harmonic substitutes to play in place of the V7 chord. For example, a more advanced improviser will inevitably find themselves grappling with how to play over the “tritone sub” in place of the original V7 chord. 

    By keeping the “diving board” or the the material over the “ii-“ chord more or less the same, as well as resolving to a simple chord tone on the I chord (water), it provides the student with a higher success rate when integrating this harmonically unfamiliar sound in place of the V7 chord. The same ideology can be used to work on implicating other sounds over the V7 chord such as “altered”, “diminished” “back door ii-V7” and the “tri-tone ii-V7” sub. The more a student has something to hang their proverbial hat on when improvising, the more it alleviates stress when trying to integrate an a new harmonic sound/device. 

    Whether you have water-wings or you are an olympic high-diver, I believe there is merit to the aforementioned ideas and I hope you find the information fun and useful with your students! So, jump in, the water’s warm!

    Written by: Adam Larson