Look: I am eager to learn stuff I don't know--which requires actively courting and posting smart disagreement.

But as you will understand, I don't like to post things that mischaracterize and are aimed to mislead.

-- Brad Delong

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Everything that appears on this blog is the copyrighted property of somebody. Often, but not always, that somebody is me. For things that are not mine, I either have obtained permission, or claim fair use. Feel free to quote me, but attribute, please. My photos and poetry are dear to my heart, and may not be used without permission. Ditto, my other intellectual property, such as charts and graphs. I'm probably willing to share. Let's talk. Violators will be damned for all eternity to the circle of hell populated by Rosanne Barr, Mrs Miller [look her up], and trombonists who are unable play in tune. You cannot possibly imagine the agony. If you have a question, email me: jazzbumpa@gmail.com. I'll answer when I feel like it. Cheers!

Thursday, December 16, 2010

Feeling Diminished

The common major and minor scales - recognizable by their sequences of whole and half steps - are not the only ways to parse the octave.  One of the others is the synthetic diminished scale.  This is a symmetric construction of strictly alternating whole and half steps, resulting in a scale of 9, rather than 8 notes.   Also, due to the symmetry, it doesn't matter which of the tones arrive at by a half tone scale step is considered the tonal center of the scale.  These four tones also define a diminished chord.  For example, one such chord contains the notes G, Bb, Db and E, any one of which can be taken as the root.  This tonal ambiguity has been exploited by composers for centuries as a way to negotiate a key change, or just sound eerie and disturbing.

The resulting scale ( G - A - Bb - C - Db - D#/Eb - E - F# - G) is also highly versatile, and sophisticated jazz improvisors use it to good effect.   I don't put myself in that category, but I have had some fun noodling on the G diminished scale.  Recently, I've tried improvising against a static C7 chord, using this scale.  In that context, the notes are, starting with G, the perfect 5th, major 6th, minor 7th, root, flat 9th, sharp 9th, major 3rd, and flat 5th (or sharp 11th.)  The dominant seventh chord is very accepting, and will accommodate any of these notes, either as basic chord tones or extensions.  This G to G approach also places the tonal center (C) in the middle of the melodic range, rather than the extremity, so the resulting melody has a rather plagal feel.

Just for kicks, I recorded this snippet using the video capture on our iMac.  There's no background to provide context, but if you have perfect pitch you can imagine the C7 chord in the background.

The sound quality of the computer's built in mike is pretty poor.   I don't really sound this harsh.

I hope.

First, two octaves of the G dimished scale, up and down, then 16 bars of improve, in a moderately quick 2/4 time.


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