What is Circle of Fifths?

In music theory, the circle of fifths is the relationship among the 12 tones of the chromatic scale, their corresponding key signatures, and the associated major and minor keys.  You can read more about it over here.

PianoCompanion has an interactive Circle of Fifths which allowing you to quickly understand where you have Major (red color), Minor (green color), Diminished (blue color) chords for Major/Minor scales and navigates through scales/chords accordingly.

The Circle of Fifths consists of the following circles/semi-circles:

  1. The first semi-circle representing the Roman numerals for relative chords of a major scale.
  2. The major scale
  3. The minor scale
  4. The semi-circle represents the Roman numerals for relative chords of a minor scale
  5. The number of sharps or flats for the selected scale.

Let’s take a look at C Major scale. Tap on C. This scale is selected one.

The Circle of Fifths shows that the following chords are major for C Major: F (IV), G (V).
These chords are minor chords for C Major: D (ii), A (vi), E (iii).
And the last chord Cb (VIIo) is diminished chord.
The parallel minor key is A Minor.

Let’s tap on the B Minor scale:

You can see that Minor chords for B Minor are: e (iv), f# (v).
The Major chords for B Minor are G (VI), D (III), A(VII).
The last chord is Diminished C# (IIo).

If you want to lock the selected scale and would like to navigate through chords of the selected scale then tap on and after that just tap on a chord: