We are going to put another circle inside
this big circle.  At the twelve o'clock
position, we are going to write
Roman Numeral I & and then on the left
this is Chord IV.  This is the 4th
Chord.  And we know in key of C
F is a 4th Chord. And then on the right,
its dominant chord, so we write the
Roman numeral V7 here. This is
the dominant  chord. You notice that
4th chord & the 5th chord likes
to be beside the key of the chord.
the key of the chord is in the center.
this is C key.
