Chord Circle to work with music notes. This is a great idea to see the whole spectrum of the notes. Make chords with numbers. Take a tone from the orange circle on position 1 of the green circle. The rest is easy. The tones 1-3-5 in the green circle are a major chord for all notes. The tones 1-b3-5 in the green circle is a minor chord for all notes. The tones 1-3-5-7 in the green circle is a mayor seventh chord for all tones. Each chord (sus2, sus4, sixth and so on) has the same numbers for all tones. So easy. And the circle of fifths is there too. Make all music.