chords, triads and chord names

• the base step (any of the seven scale steps)
• the step that is two steps above the base step
• the step that is four steps above the base step

For example:

2 4 6

1
7
6 X
5
4 X
3
2 X
1

5 7 2

2 X
1
7 X
6
5 X
4
3
2
1

a chord is named for its base step

5 7 2   the 5 chord
4 6 1   the 4 chord

A chord's members may appear in any arrangement, not just in the canonical arrangement (as shown above.)

For example:

The 1 chord may appear as:

3 5 1

1 X
7
6
5 X
4
3 X
2
1