The circle shown below is circle of fifth showing tonal areas.
One step toward the right from C at 12 o’clock is perfect fifth higher than C. One step toward the left from C is perfect fifth lower than C.
Letter on an outer side of the circle=major key
Letter on an inner side of the circle=relative minor key
For example, A and F#m are written on the three o’clock position.
Thus, relative minor key of A major key is F #minor. Just like this, you can easily find the relative scales.
Notes in a diagonal positions are tritones; one of the notes is three hole tones away from the other.
For example, B is three whole tones away from F, and vice versa.
The number of # increases as it moves toward the right from C, and number of b increases as it moves toward the left from C.
