LESSON } Jazz
This month Andy G Jones examines the use of Altered 9th chords in place of Dominant 7ths for great sounding jazz-blues vibes.
W hile the most common use of Altered chord extensions is found in jazz and jazz influenced music, there are examples in more rootsy forms, too. Many of you will be aware that Stevie Ray Vaughan commonly used the b9 on a Dominant 7th chord, albeit very briefly - notably in Texas Flood. Of course this might have been just a finger pattern that happened to feature this dissonant note.
The time to use Altered extensions on a Dominant 7th chord is when the chord is resolving down by 5th (or up by a 4th), as when G7 resolves to C. Altering the 9ths on a non resolving Dominant can sound very dissonant and ugly - there’s good dissonance and bad dissonance, and with time you’ll hear the difference. One common chord sequence that can easily be used to demonstrate this concept is the simple 12-bar blues. If we use the IV chord in bar 2, the line played over the I chord in bar 1 could use Altered 9ths, as the I chord’s root is a perfect 5th above that of the IV chord in bar 2. The same goes for the I chord in bars 3 and 4. But if you try using Altered 9ths on the IV chord which precedes a I chord (bars 2, 5 and 6), the result can be pretty distasteful - try it, to prove the point.
In our examples we start with a tribute to Stevie Ray Vaughan. After that I begin using the b9 only, then the #9 only.
The real fun starts when we combine the b9 and #9 intervals. If we play them along with the Major 3rd on a Dominant 7th, this is starting to sound more like jazz. The Altered scale and the Half-Tone, Whole-Tone Diminished scales both contain the b9, #9 and Major 3rd for instance.
From the second example on, I’m using a swung eighth-note subdivision. The beat is felt as a triplet with the first of each written pair of eigh notes felt as if it’s lasting two of the three subdivisions. The second written eighth is felt as the third note of the triplet. Think of the rhythm as being based on a constant underlying triplet pulse.
You could verbalise this rhythmic pulse as ‘di-ddl-ee’ - somewhat childish sounding perhaps but it will work. When you’re singing swung eighth notes (or quavers if you prefer to use the English terminology), try ‘doo-be, doo-be, doo-be, doo-be.
NEXT MONTH Altered 5ths on Dominant 7ths to lead from one chord to the next.
