Musical Scales

A scale is a sequence of notes that have certain harmony with each other. But they are only a mold that includes certain notes and excludes other for the sake of harmony. The chromatic scale is the scale that includes all possible notes, so when I wrote above all the notes with all the accidentals included, I wrote the chromatic scale.


Scales are more like a mathematical formula which tells us which notes are included. The most important scale is the Major Scale. It is used as reference for all the other scales, therefore it's the first you should learn. The Major Scale of C is so popular because it doesn't includes any accidentals.


So let's get to the formula. What we can observe is that the notes included in the C Major Scale are C D E F G A B. Let's start.



C is the tonic, meaning that it's the first note and that all the notes used in the scale are used relatively to this one.

 
Between C and D we have a full tone.
Between D and E we have a full tone.
Between E and F we have a semitone, remember that there are no accidentals between this two.
Between F and G there is a full tone.
Between G and A, another full tone.
A and B, a full tone. 

Finally, since a scale is a sequence that repeats itself indefinitely we must go back to the tonic. Between B and C there is a semitone (remember, no accidentals between this two either).

So the formula for a major a scale is... Tone, Tone, Semitone, Tone, Tone, Tone, Semitone. Use it with any note and there you have that note's major scale. Let's take then G.


G(tone)A(tone)B(semitone)C(tone)D(tone)E(tone)F#(semitone)G


For future reference, A is G's 2nd, B is G's 3rd, and so on until F# is the 7th. (This is for G)

Musical Notes

There are musical notes. You probably have heard of them. Hopefully you know their names. The naming is based on a specific musical scale, using letters of the alphabet, and they are:

C___D___E___F___G___A___B___C  

This is the C major scale, but it doesn't includes all the notes.  It looks like we have 7 different notes because the C repeats itself, but this one has a higher pitch than the first (this is called an octave since it's the 8th note of the scale). The other notes exist between some of the ones in the scale above, and the naming used is a modification of the name of the note next to it, adding the term flat or sharp.

From one note to the next there is a distance, called a semitone (or half step), and from one note to its next octave there are twelve semitones. 

Notes    C___C#___D___D#___E___F___F#___G___G#___A___A#___B___C

Semitone 0___1 ___2___3 ___4___5___6 ___7___8 ___9___10___11__12

The # on C# means it's a C sharp.  A sharp notation is used to indicate that the note that is shown there is not the one that is really meant to be used, but instead the note that is a semitone higher.

But that is not the only way we can express accidentals.  We also have this.

C___D♭___D___E♭___E___F___G♭___G___A♭___A___B♭___B___C

The  ♭ on D♭ means it's a D flat.  A flat is the opposite of a sharp, its pitch is one semitone lower.  It's important to notice that C# is exactly the same note as D♭.

Now, you might have noticed that between B and C, and E and F there are no accidental notes.  That is because they are already only a semitone apart in distance, leaving no space left for a new note in between., whilst for example C and D are a whole tone (or one step) away from each other. 

The use of sharp and flat depends on which scale (for more on scales see Musical Scales) the piece is written and which notes are included in such scale. The ideal is to write each note in the C major scale (ignoring if it's sharp or flat) once without repeating and without skipping.  

So let's say we have a scale with C, C# or D♭, and E (and F, G, A, B etc, it's a made up scale). We must use then D♭ instead of C# because otherwise we would be skipping D and repeating C.