Welcome to episode 121 of the LJS Podcast where today we are digging into some jazz theory and talking about secondary and backdoor dominant 7 chords. These are two concepts that are used to resolve to a tonic I chord. If you understand these concepts they can help give context to a chord progression you are improvising over. Listen in!
Listen to episode 121
In today’s episode, I’m digging into some jazz theory and talking about V7-I chord resolutions. But specifically, I’m discussing some alternatives to the common V7-I resolution. I’m talking about Secondary Dominants and the Backdoor Dominant.What’s a secondary dominant?
A secondary dominant is when a dominant 7th chord acts as a V chord of a diatonic chord other than the tonic. We call this “tonicization.” This means the chord the secondary dominant precedes now sounds like a new tonic to the listener.
What’s a backdoor dominant?
A backdoor dominant is a dominant 7th chord that substitutes the V7
chord for a bVII7 chord approaching the I chord by a whole step. This
works because the bVII7 has a lot of notes in common with an altered V7 chord. Example: Bb7-Cmaj7.
In this episode, I go over these two concepts in further detail and give specific musical examples of how secondary dominants are used in All of Me, and how backdoor dominants are used in Lady Bird and Stella by Starlight.
Why is all of this important?
I have a rule I call “The Jazz Improv Rule,” and it goes like this:
To become a better jazz improviser, you have to understand jazz harmony.
The more we understand how chord progressions work in the context of a piece of music, the more insight we can gain in how to improvise over them. It is worthwhile to spend some time digging into this stuff and make sense of it.
That’s exactly what we do in our eBook and companion course The Jazz Standards Playbook because this stuff is that important.
Start looking out for these two kinds of dominants 7th chords whenever you are working through jazz standards.
Important Links
How to Master the Backdoor Jazz Chord Progression (By Josiah Boornazian)
Hi Brent. How would you solo over the backdoor dominant? Ie for Bb7 to Cmaj7, would you take the Ab down to a G note, the F down to an E, the Bb up to the C, that sort of thing? Thanks
Another great lesson Brent , I've have learned quite a bit from your lessons and podcast during the last 2 years following you .
So glad to hear that! Thanks for listening.
So, the back door dominant is always the bVII7, but a secondary dominant can be any one of of a number of chords?
Hi Dina, you can think of the backdoor dominant that way, and that would be correct. But a secondary dominant is any dominant chord that is functioning as a V7 chord leading into a diatonic chord other than the tonic. Example: A7 to Dmin7. A7 is the secondary dominant, and Dmin7 is the ii chord in the key of concert C, but because it is being approached by the A7, to the listener, Dmin7 sound like a new tonic.
Thank you, just wanted more clarification between the two. Thanks!
When you were referring to the associated minor scale (e.g. D minor seventh as the new tonic w/the 5th chord of the scale of D minor being an A seventh), were you referring to the D minor HARMONIC (as opposed to the D minor NATURAL or D minor MELODIC) scale? I ask because the 5th chord of the D minor NATURAL scale is A minor (7th) not A dominant (7th).
Hey Mark, that's a great question. Minor tonality is a complicated thing. This is because unlike Major tonality, we are dealing with three harmonized scales: natural, harmonic, and melodic minor. So the key of D minor does not mean the natural minor scale, it means a combination of the three. From these we can derive common sets of changes, but not necessarily one set. What I will say is in both major and minor tonality the V chord is always dominant.
Here's a great podcast episode that goes deeper into minor tonality: https://www.learnjazzstandards.com/blog/ljs-podcast/learn-jazz-theory/ljs-114-minor-tonality-and-how-to-build-minor-chord-progressions-feat-dan-carillo/
Here's a post that talks about harmonizing the three scales: https://www.learnjazzstandards.com/blog/learning-jazz/jazz-theory/harmonize-minor-scales-7th-chords/
Great lesson! I have always interpreted the backdoor dominants you talked about as tritone substitutions. Would you say these two are related? are the same? depend on the way one uses them? Maybe it is just a naming difference.
Hey there Aleix! I wouldn't necessarily consider a backdoor dominant as a tritone substitution. A tritone sub implies that the chord being substituted has a root a tritone interval away from the original chord. Db7 instead of G7 for example. Whereas if we are in the key of C major, a Bb7 (backdoor) is not a tritone away from the original V chord (G7). Hope that makes sense! Here's an episode on Tritone Subs that might help further clarify: https://www.learnjazzstandards.com/blog/ljs-podcast/learn-jazz-theory/ljs-92-use-tritone-substitution-jazz-improv/
My take is that the Secondary Dominant is extending a series of resolutions into an earlier point in a song, sort of giving a different glide path into landing on the tonic.
The Backdoor Dominant just changes and maybe intensifies the resolution included routinely at a given point in the song by substituting a chord that has slightly different tensions or voice leading tones into the tonic chord. I think (and hope) that makes sense.
Hey Elliot, that's a good way of saying how both of these works in a more musical sense. Thanks for your input!
Great episode Brent! I recently discovered your site and podcast and I love it. What do you call a dominant chord that does not resolve like a secondary or backdoor dominant? For example, in the key of C, a D7 to F major. Is there a term for this kind of progression?
Hey there Chris! Thanks for listening. It's a little difficult to answer your question without knowing more context of the chords surrounding the D7 and F major. Right away I would associate a D7 as the VI7 chord in F. But again, more context might clear up how that chord is functioning diatonically or non-diatonically.
good lesson Brent thanks. i always wanted ask what guitar do use in the lessons? thanks
Hey there Dennis, thanks for listening! My trusty Ibanez Artcore. Does the job!