How to make a diatonic scale

How to make a diatonic scale

Pick a letter from A to G, accidental natural, sharp or flat. Follow through with the natural letters of the alphabet.

A

B

C

D

E

F

G

A

T

S

T

T

S

T

T

The pattern of tones and semitones from A to A is TSTTSTT. This is not TTSTTTS. It is not a diatonic scale.

We use accidentals to make a diatonic scale.

1. The first interval of the diatonic scale is T.
   • Start with the first note (A).
   • A to B is T.
   • B is the second note of the diatonic scale.
     
     
2. The second interval of the diatonic scale is T.
   • Start with the second note (B).
   • B to C is S.
   • B to C# is T.
   • The third note of the diatonic scale is C#.
     
     
3. The third interval of the diatonic scale is S.
   • Start with the third note (C#).
   • C# to D is S.
   • The fourth note is D.
     
     
4. The fourth interval of the diatonic scale is T.
   • Start with the fourth note (D).
   • D to E is T.
   • The fifth note is E.
     
     
5. The fifth interval of the diatonic scale is T.
   • Start with the fifth note (E).
   • E to F is S.
   • E to F# is T.
   • The sixth note is F#.
     
     
6. The sixth interval of the diatonic scale is T.
   • Start with the sixth note (F#).
   • F# to G is S.
   • F# to G# is T.
   • The seventh note is G#.
     
     
7. The seventh interval of the diatonic scale is S.
   • Start with the seventh note (G#).
   • G# to A is S.
   • The eighth note is A, the same as the first.

The diatonic scale of A is:

A

B

C#

D

E

F#

G#

A

T

T

S

T

T

T

S

How to work magic

Can a diatonic scale be written to D# ?

No.

D# Eb

E Fb

F E#

F# Gb

G

G# Ab

A

A# Bb

B Cb

C B#

C# Db

D

D# Eb

D#

E#

G

G#

A#

B#X

D

D#

Why not?

What is wrong with D# E# G G# A# B# D D#.

Answer: C is missing and G is repeated.

Every letter must be present in a diatonic scale.

What can we do?

We can introduce double sharps and double flats. Fx is G and Cx is D.

This is also wrong D# E# Fx G# A# B# Cx D#

Double sharps and double flats are banned from diatonic scales.

What can we do?

Rename each note to its enharmonic.

Now we have a diatonic scale.

Eb F G AB Bb C D Eb

Every key on the keyboard can be written to a diatonic scale, but not every note name. When the first name you try doesn’t work, switch to its enharmonic. It’s enharmonic will work.

C# dB

D# Eb

F# GB

G# AB

A# Bb

C B#

D

E Fb

F E#

G

A

B CB