Dominant 7b9 in a blues

**christianm77** · 03-31-2016, 09:51 AM

Originally Posted by JonR

A point I don't think anyone has mentioned is that the reason it might sound appropriate on the IV7 chord but not elsewhere is that the b9 is the blues b5 of the key - so it's right "inside", in that sense: diatonic to blues scale.

Also, IV7b9 is the same thing as #IVdim7 (a very common jazz sub, as mentioned). #IVdim7 is just a rootless IV7b9.

Even in the crudest blues, with just three major triads, melodic phrases on the IV chord will typically include the b9 (b5 of the key) as well as b7. So adding the b9 to the chord is just echoing that.

However, melodic phrases tend to resolve the b5 down to 4 (and on down via b3 to 1). The b9 on a IV7 chord tends (to my ears) to resolve upwards to the 5th of the I. So there is a potential "conflict of interest", if you like.

In fact, that's always the case with blues. The melodies - employing blues scale - always have a kind of arms length relationship with the chords: there's a constant tension between them, especially in jazz harmony, which wants to make chord changes more "interesting", even when it takes the whole sound of the music away from "blues", often leaving only the 12-bar form. In the best examples, of course, that tension is productive and expressive, and the blues can still "speak", through and above the chord changes.

Indeed!

I kind of alluded to it, but I didn't want to spell it out. But since we are going to spell it out. Sigh.

#IVdim7 from IV is one of the oldest passing chords in jazz - it practically defines the sound of Dixieland. I do wonder if it comes from the blues inflection of the melody - the same way we get V7+, Idim7 and VII7 commonly being used as a sub for V7 in 20's music on - because of the b3 going to 3 in the melody, another blue note.

And b3 and b5, two of the three principle blue notes both work great over the #IVdim7 chord. It's a good way of handling this change in tunes where it occurs (in some variants of Rhythm Changes, or Someday my Prince Will Come, say) without having to muck around with complicated scales or arpeggiate the chord (not that this is bad per se) - which is good as these passing chords can be very brief.

In terms of the blues it was in use at least form the '20s (Chimes Blues is a good example.) I daresay it also crops up in ragtime.

Anyway - re: Parker - look at bar IV of Confirmation.... It's not just in blues.

Now - how many people use a IVm in bar 6 of a blues instead of #IVo7 and you might see how Bird arrived at changes like Blues for Alice, or Chi Chi, or how Bud Powell got the idea for Dance of the Infidels.... It's a different colour again - but it's an old one. Ellington was using this passing chord in the '20s. The bebop guys turned it more into a backdoor IVm bVII7 I vibe.

It's a bit less bluesy blues and more sophisticated and slick to my ears.

You can then look at Swing era material and see how the same passing get used, and often played on top of each other in tunes like Lady Be Good, Rhythm Changes and so on. I honestly believe one of the best ways to understand bop (and swing music) is to learn as many Blues subs as you can.

**christianm77** · 03-31-2016, 10:02 AM

Also Progressions that are essentially bars 3-7 of the blues with different roots...

| Bb6 | Bb7 | Eb6 | Eo7 | Bb

| Bb6 | Bo7 | Cm7 | C#o7 | Dm7 (or Bb/D)

Yes - the second chord has a b9 :-) Notice also I write 6 not maj7 - it keeps the seventh ambiguous which means you can play a b7 if you want or a normal 7, and it reflects the older common practice of swing and bop guys. Parker, like Lester Young and Charlie Christian, was happy to play both 7 and b7 on a major chord.

So that's a common turnaround - Mean to Me & Ain't Misbehaving are commonly played this way. We also see it in It Could Happen to You, Bewitched and

ii-V/Real Book/Berklee/Spacehoppers & Loon Pants '70s Reg friendly version would be:

| Bb6 | Dm7b5 G7b9 | Cm7 | Em7b9 A7b9 | Dm7 (but it's the same thing)

Now here is a version I like that looks a bit like some progressions in Moment's Notice an Stablemates:

| Bbmaj7 | Fm7 Bb7 | Ebmaj7 | Em7b5 A7alt | Dm7 (G7)

And finally:

Bbmaj7 | Dm7b5 G7b9 | Cm7 Cm7/Bb | Em7b5 A7alt | Dm7 (G7)

Which starts to look like some of the progressions in things like Green Dolphin Street.