Scales are a group of musical pitches that create a style or a type of sound. Every scale uses a different set of pitches and each pitch is a specific distance from each other. The are many types of scales such as the Arabic Scale, the Pentatonic Scale, Blues Scales, etc. The scales we will focus on in this lesson is the chromatic scale and the diatonic scale as these are the most popular scales in western music used in Pop, Rock, Country and Rap,

Chromatic Scale

The first scale that every musician must learn is the chromatic scale.The chromatic scale has 12 pitches per octave and each pitch is a half step apart. Below is a image of what the chromatic scale looks like on a piano.

Middle C octave Chromatic Scale

The 12 highlighted keys in octave 5 is an example of the chromatic scale. Notice that each key is a half step apart meaning that each pitch is lined up side by side each other. The formula for this scale will look like this h-h-h-h-h-h-h-h-h-h-h-h (the 12th “h” will lead you into the next octave). So basically every one of the 88 keys on a grand piano is part of the chromatic scale. The chromatic scale is not a scale that is used to create a style of music. In fact if you play random keys on a piano it won’t sound very musical. The chromatic scale is more of a foundation for all other musical scales.

Diatonic Scales

The next scale you must learn is the diatonic scale. The diatonic scale has 7 pitches per octave and is used in genres such as Pop, Rock, Country and Rap music. The diatonic scale has only 2 half steps and 5 whole steps. A whole step is equal to 2 half steps. The formula for the diatonic scale looks like this w-w-h-w-w-w-h (the last “h” will lead you into the next octave). Keep in mind that these formulas define the distance of each pitch in that scale. The distance of each pitch is what gives your music that western stilo. While the diatonic scale is limited to only 7 pitches per octave there are 12 different combination of pitches giving you 12 different diatonic scales and each diatonic scale uses a different set of pitches. The 12 different diatonic scales are listed in the chart below.

List of major diatonic scales

The image below is what the diatonic scale ‘C Major Scale’ looks like on a piano.

Lets take a look at the ‘C Major Scale.’ It is named after the scale’s root note which is C. The notes that make up this scale are C — D — E – F — G — A — B – and back to C. Notice the distance between each note. If you apply the formula of the diatonic scale to the note ‘C’ you will get the rest of the notes that this major scale contains. This is true to the rest of the diatonic scales. The all follow the w — w — h – w — w — w — h formula that makes a diatonic scale.

Below is a 12 image gallery of the 12 different combinations of pitches on a piano.

12 diatonic scales on a piano

The blue highlighted keys represent the 7 pitches in that scale. The white keys are excluded and are not to be used in your composition. The gallery begins with ‘C Major Scale’ and as you click the next button you will notice that one by one a note is sharped (#). This means that the pitch of a key is raised up a semitone and one by one every pitch becomes sharped. When you get to ‘C# Major Scale’ you’ll notice that all 7 keys are sharped.

Another important thing to notice is the order in which each key is sharped. The order is as follows: F – C – G – D – A – E – B. A popular way to remember the order in which the notes get sharped is by remembering this phrase; Fat Cats Get Drunk At Every Bar.

When you get to ‘Ab Major Scale’ you’ll notice that the keys begin to descend and one by one each key is flattened (b) until you end up back to ‘C Major Scale.’

Now that we have narrowed down the number of pitches to use per octave you can literally pick any major diatonic scale and play the 7 pitches in that scale randomly and it will sound a bit more musical than it would have using the chromatic scale. So, when you’re composing a song, a good place to start is by choosing a scale to compose your entire song.

Function of each scale note (Diatonic Function)

Each one of the seven notes in a diatonic scale play a specific role.  This is called the diatonic function.  Knowing what role each note plays can help you build tension with your chord progressions or melodies.  As you already know a diatonic scale begins with a tonic which is the first scale degree.

You can think of the tonic as the sun in our solar system.  The tonic is the most important note while all the other notes are planets that orbit the tonic.  Lets take a look at C Major Scale and the role each note plays.

C major scale diatonic function

Take a look at the center of the chart above.  The rectangular box contains the notes that make up the C Major Scale.  Below each note is the function of each scale degree.  Here is the function of each scale degree:

Tonic – the tonic is the scales most important note as it is the reference point, or starting point, of all other notes.  Building a triad with this note as the root note will give you major chord.  The tonic is where the scale gets its name as well.

Super Tonic – the supertonic is the 2nd scale degree and is a whole step above the tonic.  Building a triad with this note as it’s root note will give you a minor chord.

Mediant – the mediant is a the 3rd scale degree and is the halfway point between the tonic and the dominant.  Building a triad using this note will also give you a minor chord.

Sub Dominant – the subdominant is the 4th scale degree.  It is called the subdominant because it is the same distance below the tonic as the dominant is above the tonic.  The subdominant is also the tonic of the previous diatonic scale.  You will learn more in the circle of fifths section.

Dominant – the dominant is the 5th scale degree and is the second most important note in the diatonic scale (the tonic is the 1st most important).  A triad built off this note is a major chord.  It is the highest point of the scale and creates instability and a sense of continuity.  It is the highest point because the chords that proceed is a minor then a diminished and they lead back into C Major.  A good chord progression will slowly build up to the dominant to build tension that teases the listener.  Once you have reach the highest point it can only be resolved by the tonic or the starting point of your chord progression.  That’s how you create that rollercoaster ride of emotions for your listeners.  The dominant is also the tonic of the following diatonic scale.

Sub Mediant – the submediant is the 6th scale degree.  The submediant is the hallway point between the tonic an the subdominant in descending order.

Leading Tone – the leading tone is the 7th scale degree.  It is a half step below the tonic.  Building a triad with this note will give you a diminished chord.  It is called the leading tone because it transitions back into the tonic.

Below is a list of all 12 diatonic scales and the function of each note.

List of all Major Scales and their Diatonic Function

Keep in mind that there are 12 diatonic scales because there are 12 total notes in an chromatic octave.  There is a diatonic scale for each note and each diatonic scale follows the whole step – whole step – half step –  whole step – whole step – whole step – half step formula.  So if you were to pick any key on a piano to be your tonic and apply this formula to that tonic you will get the rest of the note of that diatonic scale.