The music for “Nobody Knows You When Your Down and Out” by Eric Clapton is written in the key of C but most of the chords are played as major and/or dominant sevens.
C E A Dm A7 Dm F F#dim7 C/G A7 D7 G7 C
Please help me understand how that fits into the basic harmonized major scale, I ii iii IV V vi vii.
This song is based on an advanced concept that stems from the chord progression number system I teach in my guitar theory method. Just be sure to master the basic concepts before venturing into advanced areas like this. Music theory is a process, you know.
Jazz players like to play over dominant seven chords. Now, there’s only one seventh chord in a key (see Fretboard Theory chapter 10). But, who says you can’t change keys and play over the V7 chord each time? Well, which keys go good together? What if you take the intervals from the major scale and play each of them as a dominant seven chord? The key of C would become:
C7 D7 E7 F7 G7 A7 B7
1 2 3 4 5 6 7
So this chord sequence is actually a series of key changes. Each seventh chord is a V chord from a different key. But we used the C major scale structure as a guide to determine which keys to combine. If you want to solo over these chords, you’ll have to switch the parent major scale for every chord. Yikes, that’s a lot to keep track of! But jazz players love it.
Progressions in this new sequence are the same as the diatonic scale but now everything is a 7th chord. For example:
I IV V
I7 IV7 V7 (Most blues songs are based on this.)
I vi ii V
I7 VI7 II7 V7 (A foundational jazz progression.)
You can hop around however you want. You can even switch back and forth between 7th chords and the diatonic chords (I ii ii, etc.).
The F#diminished chord is basically an F7 chord with the root raised. This chromatic passing tone bridges the gap between the F7’s root and the C7’s fifth (hence the C7/G).
To learn more about music theory for guitar, including scales, chords, progressions, modes, and more, sign up for a free preview of my Fretboard Theory books and DVDs by using the form on this web page.
Play Until Yer Fingers Bleed!
Desi Serna (Google me!)
Scales, Chords, Progressions, and More