As promised last issue, let’s start using backing tracks to work with the most common chord progression in jazz, the ii/V. Please download the pdf and mp3 files at the end of this page to get the most benefit out of this lesson.
If you are not familiar with thinking about harmony using roman numerals, here’s a quick and dirty explanation:
The play along track we’ll be using is in the key of C, and the chord progression is D-7 / G7, where D-7 is built on the 2nd degree of the C major scale and G7 is constructed on the 5th degree of the scale. (Ex. 1) When we’re talking about notes we use regular Arabic numbers, but for chords we use Roman numerals. Lowercase means a minor type chord and uppercase indicates a major quality chord. (Ex. 2)
Let’s listen to the track from three points of view: rhythm, harmony and melody.
First, put your attention on the drums, or, more accurately, the cymbals. The drummer on this track is playing beats two and four with his left foot on the hi-hat and mostly quarter notes with his right hand on the ride cymbal, which is exactly what we do when walking a bass line. (Ex. 3) As you work on the content of your lines, be sure to stay hooked up with the ride cymbal – think of it as the “ting” for your “thump”.
Harmonically this progression is simple. The root note moves from D to G, and inside the chord only one other note changes. The D-7 chord consists of D F A C. The G7 is G B D F. If we eliminate the roots (already accounted for) and fifths (an interval that is present for both chord types), we are left with the two notes that define the quality of the chord (i.e., whether it is major, minor or dominant). The defining notes for D-7 are the third (F) and the seventh (C). On the G7, the third is B and the seventh is F. So, the important tones inside the chord move from F and C to F and B. The only note that changes (besides the roots) is the C moving down by half step to the B. (Ex. 4) Listen to the pianist’s voicings with this in mind. You can experiment with this by playing the C on the D-7 chord and the B on the G7. This will be easier to hear in the medium or high range of your bass.
Finally, we’ll work on our bass “melody” – a walking line that clearly indicates the root and chord type and that (hopefully) adds some secondary melodic interest. To make things easier for now, always play the root of the chord change on beat 1. Until you can really hear your way through this progression, I suggest that you only use chord tones on the other three beats of the measure. (Ex. 5) The most important decision your ear has to make is how you are going to go from beat 4 of one chord to beat 1 (the root) of the next chord. We’ll tackle this technique more in depth next time, but for now see what you can come up with using just the four chord tones in whatever orders you hear. Happy walking!