Question about Bebop Dominant Scale in Drop-2

[robmoreno]

Hello,

I am reading through Randy Vincent's Drop-2 Book and he mentions that in the Bebop dominant scale 3 of the diminished chords contain the same notes but one of them is different. So in the case of the C Bebop Scale in Drop 2 the diminished chord tones are D, F, Ab, B, but the exception is C, Eb, F#, A. What gives? Why is this the rule? He doesn't provide any explanation.

[pcjazz]

Hello,

I am reading throw Randy Vincent's Drop-2 Book and he mentions that in the Bebop dominant scale 3 of the diminished chords contain the same notes but one of them is different. So in the case of the C Bebop Scale in Drop 2 the diminished chord tones are D, F, Ab, B, but the exception is C, Eb, F#, A. What gives? Why is this the rule? He doesn't provide any explanation.

That doesn't seem right. Can you post a scan of the page where you found this?

[mr. beaumont]

People harmonize bebop scales?

[pcjazz]

People harmonize bebop scales?

If the OP (or Randy Vincent) means one of the Barry Harris 6-diminished scales then of course they do -- it is the foundation of BH's harmonic approach. (Barry doesn't call them "bebop scales" but others do, especially the one built on the dominant.) Those harmonized scales consist of inversions of a major 6, minor 6, dominant or dominant flat five chord alternating with inversions of their related diminished chord, so each of the four diminished inversions contains the same four notes. That's why I wanted to see the source of the OP's observation that Vincent says otherwise.

[setemupjoe]

Without seeing the book you're referencing I think I can guess what's going on here.

The dominant 7th scale known as the bebop scale in C would be

C D E F G A Bb B C

Barry Harris uses this scale as his Dominant 7th/Diminished scale.

However, when Barry harmonizes the scale he use the Ab instead of A as below,

C D E F G Ab Bb B C

This allows the chords to become C7 Dº7 back and forth through their inversions.

If you introduce the A note into the melody it's going to change whatever diminished chord would have the Ab note on top into an A.

When I started working on Barry's scales this confused me for the longest time until I realized he has two different systems going on. One for harmonized scales and one for single lines.

[pcjazz]

The dominant 7th scale known as the bebop scale in C would be

C D E F G A Bb B C

Barry Harris uses this scale as his Dominant 7th/Diminished scale.

However, when Barry harmonizes the scale he use the Ab instead of A as below,

C D E F G Ab Bb B C

Barry's C Dominant7th Diminished scale is the one with the Ab -- it is constructed from a C7 (C-E-G-Bb) chord and a B diminished chord (Ab-B-D-F). I have never heard Barry refer to the first scale you mention as a Dom7Dim scale. It is just one among many applications of a regular dominant ("mixolydian") scale. This particular application has one extra note between tonic and flat 7, per his extra note rules. This kind of confusion may be one of the reasons Barry deprecates David Baker's and others' use of the term "bebop scale."

[setemupjoe]

I stand corrected.

[pcjazz]

To the OP: Thanks for posting the page. Mark’s explanation of how Vincent came to this harmonization is correct, but it is hard to see how to use this construct harmonically. “Bebop scale” is an avoid term! Also, the fact that these chords are voiced as drop-2 has nothing to do with which notes they contain. They would have the same notes in close position, drop-3, drop 2&4, or any other voicing structure. Drop-2 voicings fit comfortably on 4 adjacent strings of the guitar in standard tuning but the voicing does not determine which notes make up the chord.

Afterthought: That F#dim chord that Vincent inserts in his harmonized scale is the diminished of G6, the sixth on the fifth of C6. If we were talking major instead of dominant there would be applications for F#dim notes in voicings for C major, by borrowing from the diminished of G6. Deeper waters here.