3 Tips for the Backdoor Cadence
Where it comes from, usage from jazz to punk rock, and how to mix it up.
From Front to Back
The Backdoor Cadence is a way to end a musical phrase without sounding typical. To understand this we should start with the Front Door, which is a ii-V-I (or 2-5-1). Take a listen to the first audio clip with a short phrase of CMaj7, Dm7, G7, and CMaj7. The last three chords bring us home to CMaj7 and end the phrase. Then listen to the second audio clip. This time you’ll hear CMaj7, Fm7, Bb7, and CMaj7. This is the Backdoor Cadence. It’s a surprising way of getting back to “home” without using the typical Front Door method.
Example 1: “Front Door” ii-V-I
Example 2: “Backdoor” iv-bVII-I
Now that we have a sense of how the back and front doors get us “home” we can look at how this works.
Where it Comes From
The Backdoor Cadence comes from the Parallel Minor. A “Parallel” scale is where we take a Major or Minor scale and switch to the other one while keeping the same starting note. C Major becomes C Minor, A Minor becomes A Major, F# Major becomes- ah, you get the idea.
Below we have a stripped down version of the Circle of Fifths. The audio examples use C Major as the main scale but the backdoor chords of Fm7 and Bb7 come from C Minor. To go from C Major to C Minor we flatten three degrees: the 3rd, 6th, and 7th which are highlighted in blue. While we are in C Minor we can use the chords and modes that fit C Minor and then return to C Major. When returning to C Major we sharpen the same three notes shown in red.
This process works in any tonality. If you are in A Major (A, B, C#, D, E, F#, G#) on the right side of the circle, then A Minor (A, B, C, D, E, F, G) is a 90° turn counter-clockwise at the top of the circle. Returning to A Major we would take the 3rd, 6th, and 7th degrees of A Minor (C, F, and G) and sharpen them.
Just remember that flattening or sharpening the 3rd, 6th, and 7th degrees is all it takes to switch between Major and Minor Parallel scales.
Usage from Jazz to Punk Rock
Next up we have our progression from the first audio example of a ii-V-I. In this we have a Pre-Dominant chord with moderate tension moving to a Dominant chord with higher tension that resolves to a Tonic chord that has low to no tension. The ii-V-I also moves in fifths. D is the fifth degree of G and G is the fifth degree of C. This gives the progression of Dm7, G7, CMaj7 a nice natural flow.
A Minor shares the same notes and chords as C Major. Below we have Dm7 as a Pre-Dominant moving to G7 as a Dominant, but G7 resolves to a Minor Tonic of Am7. Ending a Major scale movement of ii-V to a Minor scale tonic creates a Deceptive Cadence. It’s kind of like pulling the rug out from under your listener, but without knocking them over. Another cool thing that happens is that once we go to Am as a Tonic, the Dm7 and G7 chords feel like the iv and bVII chords as shown below.
The Backdoor Cadence is accessed by inverting the Deceptive Cadence. Below is C Minor with those three flat notes/degrees: the 3rd, 6th, and 7th. Aka: Eb, Ab, and Bb. By taking the path of iv to bVII to get to CMaj7 we end up with Fm7, Bb7, and CMaj7. The inversion comes from using the Pre-Dominant to Dominant in a Minor scale and moving to a Major Tonic. We’ve now pulled the “minor-scale-rug” out from under our listener and deceptively arrived at Major tonality.
While this may seem to be a Jazz technique, I assure you that you can use it anywhere. The next audio clip is a basic punk rock jam of power chords using C5, D5, G5, C5 twice. This is followed up with two rounds of C5, F5, Bb5, C5. Let me know which of these two progressions sound “punk” to you in the comments at the end of the article.
Example 2: “Front & Back Doors of Punk”
How to Mix it Up
Sticking with the Punk Rock mentality I’ll want to do something that stands out. To this I’ll use C5, F5, Bb5, C5 in the lower register so that some lead guitar can come in at a higher register. The modes that line up with C5, F5, and Bb5 are C Ionian, F Dorian, and Bb Mixolydian. I don’t want to stick to these too much because conformity is not the punk rock way.
To mix things up I’ll use E Minor Pentatonic over the C5 chord. The reason for this is that C Ionian’s third degree note is E. The note E starts E Phrygian, which is a minor mode. So, I’ll play a Minor Pentatonic scale over the third degree of the chord. This will work great because a C5 chord is just the notes C and G. The lead guitar can choose from the notes E, G, A, B, and D. With only the note G in the chord and scale, the lead guitar can fill in the sonic space with E, A, B, and D or double up on G.
F5 uses F Dorian and will add three flat notes: Eb, Ab, and Bb. I’ll stick with F Dorian (F, G, Ab, Bb, C, D, and Eb) because flattening three notes is already a great non-conformist move. It also allows the lead guitar to use F Minor Pentatonic, which is just a half-step up from E Minor Pentatonic.
The third chord of Bb5 should use Bb Mixolydian. This is a Dominant mode. To mix this one up I’ll play D Locrian (D, Eb, F, G, Ab, Bb, C). Locrian is also a Dominant mode and is usually avoided due to its highly dissonant sound. D Locrian also uses the same notes as Bb Mixolydian, so there’s no need to learn a new scale. We’re just making D the central note for a moment so that the Locrian dissonance comes through a bit more. Punk rock is all about dissonance, so let’s give it a go!
Example 4: “Backdoor Laidback Punk with Lead Guitar”
Remember:
You can figure out which notes are changed by flattening the 3rd, 6th, and 7th degrees of a Major Scale or sharpening the 3rd, 6th, and 7th degrees of a Minor Scale.
The Backdoor Cadence is a iv-bVII-I, so you can use a formal to quickly find the chords.
Pentatonic scales work great when they start from the Tonic chord’s third degree. If the third degree starts a minor chord, then use Minor Pentatonic.
Try the Backdoor Cadence in any style you like and listen to where it takes you. Let me and everyone else know if you find something cool. And, as always, you can also ask questions in the comments section. Until next time!
