Re: [Harp-L] II V I

[Richard Hunter <turtlehill@xxxxxxxxxxxxx>]

"John F. Potts" wrote:
<I am very intrigued by the concept of "scale substitutions.''  Is  
<there a reference or a formula for determining which scales can be  
<"substituted" for use over which chords?  Or can you at least  
<elaborate upon how this determination is made?

Most substitutions involve the V7 chord. The first question with regard to this chord is: what's the chord substitution?  The second question is: what scales go with the substituted chord?

A very common substitution is the flat-5 substitution, where a dominant 7 chord distanced a diminished fifth from the original dominant 7 chord is used.  So, for example:
--Db7 is substituted for G7, in which case a Db mixolydian scale can be used over the G7 chord
--F#7 is substituted for C7, in which case an F# mixolydian scale can be used over the C7 chord
--B7 is substituted for F7, in which case a B mixolydian scale can be used over the F7 chord

Less common, but very cool, a dominant 7 chord that shares 2 tones with the original chord can be substituted. In this case:
--Eb7, F#7, or A7 can be substituted for a C7 chord
--Bb7, Db7, or E7 can be substituted for a G7 chord

Obviously the scale tones that go with these substitutions can sound pretty unusual in the context of a straight country or Chicago blues, so it's a good idea to think about what emotional effect you're going for before you set one of these things in motion.

Finally, a really, really simple short cut to coolness that works on almost any chord is to play a line based on the same chord type as the original chord, but 1/2 step higher.  So, for example, you play an F# minor scale over an F minor chord.  Like most short cuts, this works best in moderation--play an entire solo that way and you'll sound totally off-kilter, but drop it in for a bar or two and you sound super-cool.

Regards, Richard Hunter

author, "Jazz Harp"
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