You just need to understand two things to write out all twelve diatonic major scales:
1) The space pattern between notes (structure) and
2) How sharps (#) and flats (b) control those spaces.
As a review, the key of C is the only key that does not require the use of sharps or flats to become a diatonic major scale; begin on C, continue up the 7 letter music alphabet (when you get to G, go to A and continue up):
C D E F G A B C
The pattern above shows the larger “whole-step” spaces versus the smaller “half-step” spaces. Remember, E to F and B to C are the only intervals in music that are “natural” half-steps, as indicated above. This means no sharp (#) or flat (b) is required to make it a half step. The pattern of spaces between the notes is Diatonic Major (a seven-tone major scale). That pattern as seen above is:
whole whole half whole whole whole half
1 1 ½ 1 1 1 ½
Repeat it 10 times – memorize it. Got it? Say it again, 10 times: 2-wholes, 1-half, 3-wholes, 1-half. In order to write out the other eleven keys in music, you must know this pattern by heart. Since most music is based on diatonic major keys, you will use it the rest of your musical life! So memorize it.
Okay, fasten your seat belt – here we go. Let’s write out seven notes, but this time we’ll start on G:
G A B C D E F G
1 1 ½ 1 1 ½ 1
The space pattern here is whole, whole, half, whole, whole, half, whole – 2-wholes, 1-half, 2-wholes, 1-half. Starting on G shifted the pattern a bit, but we can easily adjust it with a sharp #. Observe:
G A B C D E F# G
1 1 ½ 1 1 1 ½
Remember, sharps (#) raise (increase) a pitch up by a half-step. Adding the sharp to F increased the space by a half-step, giving us the whole-step we needed between E and F. At the same time, it decreased the whole step between F and G, resulting in a half-step at the end. The resulting pattern of spaces became Diatonic Major.
Thus, the key of G has one sharp: F#. Without it, starting on G does not give us our diatonic major pattern of spaces.
Let’s do another one, this time we’ll begin on D:
D E F G A B C D
1 ½ 1 1 1 ½ 1
Notice I always begin by writing out the notes up the alphabet, then adjust the spaces with sharps or flats later. Obviously, this pattern is not diatonic major: 1 ½ 1 1 1 ½ 1 – not the 1 1 ½ 1 1 1 ½ we need. We need two whole-steps in the beginning, and instead that second space is a half step. So, let’s fix that first:
D E F# G A B C D
1 1 ½ 1 1 ½ 1
Cool, as before we killed two birds with one stone: adding the F# gave us our 2 whole-step spaces in the beginning, while at the same time decreasing that next whole step space giving us the next half-step we needed.
All that is left to do is get the 3 whole steps and one half step at the end. So, we’ll increase the space between B and C by making the C a C#:
D E F# G A B C# D
1 1 ½ 1 1 1 ½
And there we are, back to our 1 1 ½ 1 1 1 ½ diatonic pattern of spaces.
Note: there are two ways to adjust spaces: add a sharp (#) to the note in front, are add a flat (b) to the note in back. Either way results in the space becoming a half-step larger, i.e. it turns a 1/2 step into a 1 step:
B C becomes B C# or Bb C
½ 1 1
How you determine to increase that half-step depends on the effect it is going to have on the spaces surrounding it, but more particularly which key you are in.
Similarly, we can decrease whole-steps to half-steps:
A B becomes A Bb or A# B
1 ½ ½
So far, we have only been doing sharp keys. Fact is, keys are either sharp keys, or flat keys, never mixed, i.e there is no such thing as a key that contains both sharps and flats – either / or, never both! Period, end of story.
Here is a trick for knowing when a key has sharps or flats: with the exception of F, all flat keys have the word “Flat” as part of their name. Bb (B flat) is obviously a flat key. Eb is obviously a flat key. Ab is obviously a flat key, and so on.
Conversely, C# is obviously a sharp key, G# is obviously a sharp key. All keys with the word Sharp are obviously sharp keys. F is a flat key, as mentioned above. And C is the natural key (neither sharps or flats). Other than these two exceptions, all keys with no word after their name are also sharp keys: D, E, G, A, B are all sharp keys.
Sharp keys: C#, D, D#, E, F#, G, G#, A, A#, B
Flat keys: F, Bb, Db, Eb, Gb, Ab
C = no # or b
Let’s do a flat key. Here is F:
F G A B C D E F
1 1 1 ½ 1 1 ½
By now, you can quickly recognize that this pattern of spaces is not diatonic major. We know F is a flat key, so we will fix it by decreasing that B to a Bb:
F G A Bb C D E F
1 1 ½ 1 1 1 ½
That also adjusted the next space to a whole, resulting in the diatonic major scale pattern.
Let’s do another flat key:
Bb C D E F G A Bb
1 1 1 ½ 1 1 ½
Obviously not a diatonic major scale. The whole-step space between D and E needs to be decreased to a half-step:
Bb C D Eb F G A Bb
1 1 ½ 1 1 1 ½
It also opened up the space between Eb and F – and there we are, the key of Bb has two flats: Bb and Eb.
Okay, you knew this was coming: your homework is to take all the remaining keys and write them out, using the same technique: pick a key, write it out up the alphabet, determine if it will require sharps or flats, and modify the spaces until they become diatonic major.
Our next blog will give a chart with all 12 keys written out. You have the entire weekend to do it – then you can see how well you did. Good luck. Until then, I remain
Musically yours,
Al
by Al Dinardi
30 Jan 2010 at 14:26
Sharps or flats are required to adjust the interval spaces between the notes inside scales so they fit the pattern for that particular scale. Remembering that C is the only key that is a natural diatonic scale (no sharps or flats required), all other keys require either sharps or flats, since the spaces between the notes is not a diatonic pattern, or “sound”. The “doe ray me fah so lah tee doe” sound is diatonic major, made up of a specific pattern of whole-steps and half-steps to sound that way. Starting on any note other than C produces a different pattern, a different sound. So, we use sharps or flats to adjust the spaces to get the same pattern of sound starting on a different note.
If you begin on a note that has the word “flat” as part of it’s name, for example Bb – we are in a flat key, and will use flats to adjust the spaces – the only exception is F, which is also a flat key. Otherwise, all other keys are sharp keys, requiring sharps to adjust the spaces. So, the key of A would be a sharp key, since it does not have the word “flat” as part of it’s name. A# is also a sharp key, since it has “sharp” as part of it’s name. But Ab would be a flat key, since it has “flat” as part of it’s name.
Hope this helps. See the latest blog for more help.
Al
by sheridinardi
30 Jan 2010 at 11:45
This is great!!! I look forward to all the doors it opens for viewers of Music Theory Forum! To have the proverbial missing pieces of the puzzle come into place is a joyous experience of understanding… the chocolate ice cream of thinking! Get ready for a great ride and unlimited flavors of ice cream!
PS The black and white key arrangement on a piano makes sense in light of a C diatonic major scale and is a visual picture of the “natural” half steps of BC and EF.
by Jimmy
30 Jan 2010 at 01:53
Ok, whoa, whoa, whoa!! I’m gonna need longer than the just the weekend to decipher all this. The first three blogs I was doing just fine but you went to 4th gear in this one. I’ll get it………I promise! Just give me a little more time. Having a little trouble figuring out why a certain key is a flat or sharp. I’ll be honest…..you lost me there. BTW, this is the best thing since chocolate ice cream!! 🙂