CHORD NUMBERS AND INVERSIONS

We can build a major chord on each note of the scale. We can use Roman numerals to mark them. If the chord is built on the first note of the scale, we call it a I (One) chord.

If the chord is built on the 4th note of the scale, we call it a IV (Four) chord.

If it is built on the 5th note of the scale, we call it a V (Five) chord.

In C Major, C is the first note of the scale, so we build the I (One) chord on C.
F is the 4th note of the scale, so we build the IV (Four) chord on F.
G is the 5th note of the scale, so let's build the V (Five) chord on G.

After we build the chords in root position , we can change the notes around.

Instead of a C,E,G chord, we can put the E as the bottom note and we now have E,G,C as the tones of the chord. We call this the first inversion of the chord.

Put the G on the bottom to make a G,C,E chord and this is the second inversion of the chord.