You can easily harmonize any songs with
three basic chords.  The C Chord, the F Chord
the G7 chord. And they are the 1st Chord
the 4th chord and the 5th chord.
When we use the circle you need to know your Roman numerals
so the first chord for C key is a Roman
numeral 1 & the 4th chord, F Chord
is Roman numeral IV & the 5th chord
is Roman numeral V7
The 7 signifies this a dominant chord.
You need to understand chords in terms
of Roman numerals and this is the
quickest way to learn how to play in all
12 keys. If you use this dynamic circle
you'll be able to find the 1st chord,
the 4th chord & the 5th chord
all 12 keys easily.
This magic circle is not static. It can
move. It will show you the 1st chord
the IV chord
& the dominant  chord of all 12 keys
