The above principles are not intended to define all that is possible in
harmony. They are a way of describing what tonal composers have usually
written.in simple pieces. By following these principles your music has a
better chance of pleasing you in the same way that you have been pleased
by other compositions.

The concepts described above can be summarized in a chart that
we will call the "chord board." The "chord board" is for playing a sort of
compositional game. To play, you start with any one of the circles
numbered "\" for tonic, and then you move to other circles to build a
chord progression. Your last chord should be another I, preferably
preceded by a V. As in most board games, you can move only in certain
ways:

1) You can move along any of the lines that connect chords. Most of the
time this means you can move either horizontally, vertically, or diago-
nally.

2) You can't skip over chords.

3) You can move horizontally right-ward any number of times consecu-
tively, but any other direction only twice consecutively at the most.

4) At any time you can jump to a chord of the same name (if you're on a
ii spot you can jump to any other ii). This is needed if you reach an edge
of the board.

The thicker lines are an extra help; they indicate the stronger type
of movement. The strong line from vii to I shows that vii is used like V
to return to the tonic.

The chord board takes no account, of course, of the greater
concerns that motivate composers. But it is a fun way to experiment with
harmony.

You can use the chord board to make up some progressions for
your own amusement, and you might want to try using it to compose a
whole song. A similar chord board will work for minor keys: