Howard is right in saying that the rules come after the music has been played. This is how music theory came about in the first place. This goes all the way back to Pythagoras experimenting with taut strings in an effort to determine if music were inherent in nature, and his basic attempt to describe nature in terms of numbers and ratios.

And he found that this was indeed the case!

Then musicians studied what other musicians did that was successful in terms of creating the desired effects, and thus the "rules" of music theory were born.

One of the best lessons in music theory that I had at the U. of Washington School of Music was sitting in class with a pencil in my hand and a folio of Beethoven string quartets, writing in what chords the quartet was playing—each instrument playing an individual note, but looked at "vertically," they constituted a four note chord. And what were those notes? And what preceded this chord and where is it going? And why did Beethoven write it that way?

Music theory is not necessarily a bunch of "restrictive rules" that will limit "natural musicianship" as I had been warned by a few other folkies, but an exploration of good musicians had done, which proved successful, and generally, what was possible.

When you find an "odd-ball" out of key note in a particular chord within a piece of music, such as an E major with its G# when you're in the key of C, notice the chord that follows. More often than not, in that situation, it will go to either an Am or an F major.

The maverick G# resolves to an A in both the Am and the F major chords.

You build a smidgen of tension with the out-of-key (or "accidental") note. "Drop the other shoe." Then when you play the Am or F major, the G# moves up a half-step to the A, and the other shoe drops.

It's a little thing, perhaps, but it works very nicely. A little salt on what could otherwise be a somewhat bland dish.

Now, of course, this, like salt, can be overdone, with unpleasant results!

Don Firth