All About Chords, part 1
(20 Nov 02)
How does this sound: instead of sitting down with a bunch of boring theory textbooks, you can use *music* to understand how harmony and chords work on the guitar. Does that sound like a cool way to learn about guitar harmony?
If you think so, then that's how we'll start our exploration of chords: with a tune. Actually, a chunk from a tune. Let's check it out.
Strum each of these chords twice, anywhere on the fretboard.
C, Am, F, G7, C
Now, let's work backwards to understand just how this musical phrase *works*, in terms of the chords that we find in it.
G7 to C
Look at the last chord change: G7 to C. Why do we play this? Why not play an Eb7b9 or an F#13b5? Or even something simple like an F major? What's so great about a G7? Well, play those other chords with C, and listen to what your ear says about each. That will give you the best answer.
The most satisfying chord to play before the C is the G7. What the heck does that mean: "satisfying?" It partially means what we *expect* to hear, what we are accustomed to hearing, and what we've heard in a billion other phrases and tunes.
So, what is it about the G7 that makes playing it before C so satisfying? A few things. Let's talk about 'em:
- The sweet note of the G7: B
- The no-no interval, or tritone
- The movement of a perfect 4th up from G to C
Let's look at each of these under our musical magnifying glass.
The sweet note
The sweet note of a chord is its third: In G7, that's a B. Play a G7 without a B and you'll see why B is sweet.
The G7 sounds pretty drab without that B, doesn't it? It's like putting up a Christmas tree but not decorating it. Let's put that B back in before things get out of hand.
The B is what gives the G7 its peppy, optimistic sound. And there's another reason why B is important in helping G7 to C sound satisfying.
B is just a wee little bitty bit shy, one half-step shy to be exact, from C. This closeness of B to C causes tension. It's like that box of chocolate Pop Tarts way up on the top shelf that the little kid can almost but not quite reach. We like to have this tension and resolution combo, and the B helps provide it.
The no-no interval, or tritone
There's another reason why the G7 moves so satisfyingly to the C. It's called the tritone interval. This interval will make your straight hair curly, your milk go sour, and will propel the G7 smack into the C with cataclysmic force. (That last sentence sounds great if you pretend you're Charlton Heston.)
The tritone is an *interval*, which means it's two notes: B and F. Play a B and an F, listening to how unusual they sound together and how much tension they produce. In fact, play this tab:
Tritone to minor 6th
This movement of the unstable tritone to the stable minor 6th (the C and E notes) is another reason why G7 to C sounds good.
By the way, there's an interesting newsgroup message that relates some of the beliefs that Ancient Greeks and others had about the tritone. To read this message, surf to this subdomain: groups.google.com. When you're there, click Advanced Groups Search. Then, enter this text in the box that reads "Message ID": cornell.791886334@michigan
Up a fourth
What's the last reason why G7 to C will put a smile in your step and a twang in your Tang? What's the root of the G7? The G. What's the root of the C chord? The C. What's the interval between these two roots, G and C? A perfect fourth. *Chord movement by an ascending perfect fourth generally sounds good.*
We can even take that a bit further by saying that a huge number of chord movements in most types of songs use ascending perfect fourths (or a descending perfect 5th).
Listen to some examples of this interval: play a D note followed by a G note. Just play notes now, not chords. Then, play a G followed by a C note, and an A followed by a D. Now, let's flesh this idea out by playing a chord progression that moves only in fourths. Play this:
C, F, B dim, Em, Am, Dm, G7, C
Notice I said "fourths" and not perfect fourths. Almost all of the movements here are ascending perfect fourths. One movement, from F to B, is not a perfect fourth, but our furry friend the tritone.
How does this progression in all fourths sound to you? Personally, I think it's pretty cool. Ya got tension from the B dim and G7, ya got a mix of all the chord types in the major scale: minor, diminished, major, and you're moving by one of your ear's favorite intervals: the ascending perfect fourth. All is well with the universe. Go in peace.