One notion that stayed with me for a good while is the description of the progression bVII7 - I as a minor plagal cadence. That is, with the eleventh in the bass and a major seven typically added, whether in the voicing or in improvising. I think I got it from one of Reed Kotler’s mailing lists, and who knows where he got it from.
I’m not too sure what double plagal means in the context of the other Beatles progression, but I’ll try to figure it out.
If you’re just asking where the term comes from:
A plagal cadence is IV-I. A bVII-IV-I can be thought of as a chain of plagal cadences. the bVII-IV is a plagal cadence on the IV, which in turn is a plagal cadence resolving down to the I.
So, in the key of C, a bVII-IV-I progression is Bb-F-C. Bb-F is a IV-I in the key of F, and the F-C is a IV-I in the key of C. Hence the term “double plagal.”
Got it. I’m not around my keyboards now, but I wonder how it would sound with a #11 on the bVII7 on the way to the IV. Probably too jazzy for a rock tune. How would your average guitar player voice these chords (including extensions up to the 13th)?
Not at all “too jazzy”. In fact it’s quite common. Often in rock you have a melody which is first stated on I, then repeated over bVII and IV respectively. That melody is likely to have the 3rd in it (on the I) which is also the #11th of the bVII.
On guitar take an open position A chord (barre 1st finger) and then with your 2nd finger play a G in the bass (6th string). (ok, technically this is an A7/G but it can also be considered a Gmaj7(#11) even though some important notes seem to be missing. Often they’ll be in the melody anyway. A jazz musician would not make a distinction since they’re easily substitutable).
Do the same thing on the open D major chord, but here half barre 2nd fret (1st finger) and use your 2nd finger to get the C bass note.
It’s probably hard to go 3 Zeppelin tunes without hearing this. (e.g. Your Time is Gonna Come, Thank You, Stairway (briefly during the transition to the last section), etc.)
I’m having a little trouble getting this. The first chord you describe has notes G E A C#. Gmaj7#11 would be G B D F# C#. I don’t follow the analysis.
Well yes that’s true, but they’re all part of the same extended harmony. A jazz musician would see them as the same. The further you delve into extended harmonies the more you realize that every chord is a scale and every scale is a chord (almost. When there’s a major 3rd, we omit the 11th unless it’s #).
So when a jazz musician sees Gmaj7, he sees G, B, D, F#, A, E. And when we add the #11 we can also throw in there the C#.
Now the 5th is commonly omitted since it really gives the least amount of info about the harmony so we don’t need the D. As to the B and F#, well, chances are someone else will play them, or they’ll be part of a melodic figure or something.
Thank You by Zep is a perfect example.
The bass is D, C, G. It’s a very clear I, bVII, IV progression. The little melodic motive that repeats on each chord has the notes E, F#, G.
You can analyze this in a number of ways (and admittedly thinking of the 2nd chord as a C with a #11 is probably not the best way to go. Remember, my earlier post in response to Jeladin was simply answering if if it would sound OK to add a #11 on the bVII). And there really is no perfect way to analyze it that I can think of offhand which is both accurate and reflects the simplicity of it. After reading this thread I’d probably just say “double plagal in D” and then treat the melody as something separate.
If Paige kept the A in there throughout (3rd string, 2nd fret), thus keeping the entire D chord intact and just changing the bass note, it would be easy to write it as D, D7/C (or even just D/C), D/G, and it wouldn’t sound very different. But that would be a lot harder to play on the guitar so the A becomes an open G for the C and G chords.
You can think of it as D, Cadd9, Gmaj7, and this is probably the best way to write it since in the sheet music you have the melody written in. In fact, forget what I said earlier about there being no perfect way. This is the one I think.
But you could also include the melody notes in your harmonic analysis and so the C chord could very well be analyzed as a Cmaj9(#11). The major 7th is missing, but it’s there theoretically, since you know what key/mode you’re in (G/D mixo).
Makes it much easier to hear a song and instantly play it back, too. I can’t imagine I’d have 1/10th the ability to do this without having the Theory education I received back in HS, and the resulting paradigm shift that ensued.
Sure, there may be some folks who could hear a I VI II V (or a I vi ii V for that matter 
) change in a song and immediately play it back on an instrument without calling it or thinking about it as a “1 6 2 5”, but I have to believe that it’s a tougher road to have travelled.
I vaguely recall hearing about augmented 6ths, but checked out the Wiki page during the blues progression discussion…I’ve been playing this without even realizing it with my left hand (keyboard) on the common blues turnaround by combining a “walk-down” with a “walk-up”; (read from bass up) root note, b7th+3rd (I7), 6th+4th (IV), b6th+#4th (+6th(!)), 5th/5th octave up (V). The augmented 6th sounds better to my ears as just the 2-note interval than a full bVI7…less is more.
Augmented sixths – that language by which we beat our children. This is probably the one area where so-called jazz theory is simpler by treating these sounds as tritone subs or as various other suspended appoggiaturas.
Moe That’s the way I would play it as well, leave the #11 as a (critical) option, for soloing, since that’s where the tonality swings. I haven’t played with a cover band for like ten years, just doing jazz and piano-based cocktail now, so I wasn’t sure how it would sound.