countdown (2002)

the black keys. blues/rock, Akron OH USA

key: A blues
mode: A C D D# E G
melody: TA d mə f s
form: strophic
meter: duple

English function names: tonic   subdominant
Tagg (modified):        home    counterpoise (away)
Riemann:                T7 or 6 S7
Scale degrees:          I7 or 6 IV7
Chords:                 A7 or A6 D7

intro
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |
drums:
|/ / / / |
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |

verse 1:
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |
 D7                             A6
|/ / / / |/ / / / |/ / / / |/ / / / |
 A6
|/ / / / |

verse 2:
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |
 D7                             A6
|/ / / / |/ / / / |/ / / / |/ / / / |
 A6
|/ / / / |/ / / / |/ / / / |

verse 3:
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |
 D7
|/ / / / |/ / / / |/ / / / |/ / / / |
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |

interlude:
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |

verse 4 (same as 2):
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |
 D7                             A6
|/ / / / |/ / / / |/ / / / |/ / / / |
 A6
|/ / / / |/ / / / |/ / / / |

verse 5 (same as 3):
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |
 D7
|/ / / / |/ / / / |/ / / / |/ / / / |
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |

outro:
 A6
|/ / / / |/ / / / |/ / / / |/ / / / |
 A6
|/ / / / |/ / / / |/

At first, I was all about the A7-D7 pairing, but eventually I realized I'm actually not hearing a 7 in the A chord. The melodic riff is between A and F#, making it more of an A6 chord. The 7 in the D chord also is part of a melodic riff, so… This is always a tricky thing, making these decisions. Like I always say, that's why they call it theory and not science.

What is a 6 chord, anyway? We don't really do 6 chords in classical music. In jazz, it's a flavor, just like the dominant 7 chord is. In classical, we don't really do flavor in that way (not until we get out of common practice and into Debussy and Ravel…); we are more concerned with function. The 7 in a dominant 7 in classical music serves a specific function — it has a job, and that job is to say we are really going back to the tonic. In more harmonically complex music, it might say other things like: we are pretending to go to the tonic but instead we are going to fool you with this other submediant chord (the relative minor chord) ha ha, or we are temporarily going to make this chord more important and tonic-esque, or we are semi-permanently or completely permanently moving to a totally new tonic. In a two-chord song, we don't have those choices; it's just home and not home.

Blues and its children (jazz, rock, gospel, and so on) feel differently about the dominant 7. It's a nice sound, so we'll use it on the tonic, too. In these styles, the dominant 7 does not have the function that it does in classical music — although, yes, you'll hear it used as an incoming chord, too — but because it's used freely and in any function, the sound of that chord does not signify what it does in classical music (and most European folk as well). Weren't we talking about the 6 chord? Yes.

A 6 chord is a tonic chord with a little bit of flavor; a different flavor to the dominant 7. Many blues melodies, many Appalachian folksong melodies, many African melodies are pentatonic — they have a particular five note melodic set. Many other cultures use this set, too — the "Asian" melodic trope is pentatonic. The black keys on the piano are a pentatonic set; perhaps this is why they chose their band name. It is distinctly less common on the European mainland. I suspect that the flavor of the 6 chord may be from the pentatonic set. This flavor, as I mentioned, is almost exclusively used for tonic chords, as it is here.

You could use a dominant 7 chord where the 6 chord is and it would sound fine. You could even play the whole thing with no dominant 7 chords, no 6 chords, and it would still work. But clearly, there is a lovely sense of motion created with those two little two-note oscillating riffs in each chord.

There's another interesting two-note oscillation in the "bass" (lower end of the guitar, really) during the first phrase of the verse. The two notes are C and A. If we have a C, then aren't we talking about an A minor chord and not an A major chord? Yes and no, because what we are really talking about is the blues. As we've seen before, the blues is its own tonality and happily encompasses the minor third, the major third, and everything in between those two in its orbit. We could say that perhaps this is more accurate…

 Am
|/ / / / |/ / / / |/ / / / |/ / / / |
 D7                             A6
|/ / / / |/ / / / |/ / / / |/ / / / |
 A6
|/ / / / |

…except the organ pad in the upper register still has that pesky C# in it. Who wins? The bass riff or the organ pad? For me, it's the organ pad. For you, it may be otherwise. That's theory for you.