Circle of 4th's ( flats ) Lesson by flyinglibra51

Last time we talked about writing scales. I'll continue with the 
circle of 4th's and show you how we place flats in the scales.

Remember our formula is W W H W W W H which is W = whole step
and H = half step. It will still be necessary to shorten or lengthen 
by using an accidental, which in this case will be a flattened note.

We start with the C major scale and remember it has no sharps or flats.

C   D   E   F   G   A   B   C
1   2   3   4   5   6   7   8/1
  W   W   H   W   W   W   H

C to D is a whole step, D to E is a whole step
E to F is a half step, F to G is a whole step,
G to A is a whole step, A to B is a whole step,
and B to C is a half step, so our formula works

This time we use the 4th degree of the scale, the name for circle of 4th's
by the way, and we get the following starting at F, which is the 4th.

F  G  A  Bb  C  D  E  F   we see right away that B to C is a half step
                          but it is in a position where a whole step is
                          called for. Also we see A to B is a whole step
                          but is in the position where a half step is
                          called for. By Flattening the B to Bb we 
                          correct so the formula works. This will be 
                          the process through out the rest of the scales

Bb  C  D  E  F  G  A  Bb  B was the 4th degree so that is the next
                          scale we use. We carry over our Bb just like
                          in the circle of 5th's. So B is still flat.
                          The 4th degrees from here out are flat. We 
                          can check our formula though to make sure
                          this is still correct. The Bb now makes this 
                          the Bb major scale. The next 4th degree is E.
                 
Eb  F  G  Ab  Bb  C  D  Eb  Checking we see our formula is still intact.
                            And we now have the Eb major scale.

Ab  Bb  C  Db  Eb  F  G  Ab -- A is the next 4th degree making this the
                               Ab major scale. D is the next 4th degree.

Db  Eb  F  Gb  Ab  Bb  C  Db -- As always we still carry over our flats
                                to the next scale.

Gb  Ab  Bb  Cb  Db  Eb  F  Gb -- G is flat so this is Gb major scale.

Cb  Db  Eb  Fb  Gb  Ab  Bb  Cb -- The Cb scale is all flat notes.
                                  The Cb = a B natural in the Gb scale
                                  so our math formula will work. It is 
                                  for theory though not used for real.
flyinglibra51
God Bless Glen Travis Campbell