The two chords of classical music

In the days of my small-town youth, much ado was made over the supposed lack of musicality in rock music, music built, so they said, around only three chords. The great irony is that many of the same people who dismissed rock music were fans of early 19th-century classical music, which is built around only two chords.

Maybe some other time I'll revisit that senseless old rock vs. classical debate and speculate about how it might have steered me towards being a fan of progressive rock.

For now, let's take a look at the two chords of classical music. The two chords are the tonic chord, which we call [one], and the dominant chord, now known as [five]. To be specific, the dominant chord of classical music is a seventh chord, [five]⁷.

In the key of C, we're talking about the chords C and G⁷.

In a minor key, the tonic chord is minor, [one]m, but the dominant chord is still major, still the same [five]⁷. But for now, let's keep things simple by sticking with the major key example.

Classical music is sort of like a sports match, with the ball endlessly lobbed from [one] to [five], back to [one], back to [five], and so on. Within this extremely constrained harmonic world, composers nonetheless managed to create some compelling and complex music. They found various ways to slip in other chords on the way from [one] to [five] and back, and to create bits af drama, making you wonder how long [five] was going to hold onto the ball and how [one] would ever get it back. But [one] always won the final match.

I'm sure there were riots and looting the first time a composer ever dared to break the formula and end a piece with a chord other than [one]. Like wearing mismatched socks or marrying someone your parents didn't approve, it just wasn't done.

To expand their narrow world just a little bit, classical composers were very free about temporarily changing keys. Let's say we're in the key of C, and the interplay between C and G7 starts to wear thin. We then let G pretend to be [one] for a while, and let G fight it out with its dominant chord, D7. When that fight runs its course, G would turn back into G7, reclaim its dominant role, and you'd end up back at C again.

Of course I'm oversimplifying classical music here, and you could spend years studying its subtle details. But it's important to understand this centerpiece of classical music, because it lives on. You can't fully understand rock chords without grasping the interplay between [one] and [five]. It's still alive and kicking in rock music, but, thankfully, it's not the only card in the deck.

We'll come back to these two chords again and again over the next few months. Here are a few key lessons to take home today:

• [one] and [five] are rivals, fated to fight each other for control of the musical playing field.
  
• Every chord has its own private dominant chord, its own [five] or [five]⁷. That adds up to a lot of extra chords available for your use at a moment's notice.
• For the most familiar and powerful chord movement, you'll want to build up to a [five] chord, and then resolve back to the [one] chord.