Introduction to Intervals and the Chromatic Scale

What is a note? A note is a symbol or letter name used in music to indicate the pitch and length . Pure music theory is concerned with harmony, therefore the relationship between notes in this course will focus on the concept of pitch only.

What is an interval? An interval is simply the measure of distance between two notes.

Like writing words on a page, we construct our musical sentences using letters from the musical alphabet. Music borrows letter names from the alphabet, restricting its use to just the first seven letters.

The Seven Musical Notes

Seven Musical Notes

How is it possible to create any meaningful music with just seven notes? How does this work? The secret is in linking these seven notes to produce an interlocking series of repeating notes. This is possible because note names are divided into a series of twelve repeating notes.

I know exactly what you are thinking right now. We just said that music is divided into twelve repeating notes, however we are only using the first seven letters of the alphabet. How do you explain the other five musical notes?

The remaining five notes are given specific function and names, and are inserted between the seven letters we borrowed from the alphabet. These five notes contain accidentals and are defined as sharps or flats. This subject will be covered in detail to follow. The resulting twelve notes are referred to as the Chromatic Scale .

The Twelve Musical Notes

Twelve Musical Notes

Sharps, Flats, and Naturals

As you would have noticed in the above Chromatic Scale illustration, the notes placed between the seven notes borrowed from the alphabet contain symbols. As mentioned, these symbols are referred to as Sharps and Flats, and in musical terms they are referred to as accidentals . Their function is to raise or lower the pitch of a note by one half-step.


The accidental sign used to raise the pitch of a note is called a SHARP, # .For example, raising the note C by one half-step gives you C#.


The accidental sign used to lower the pitch of a note by a half step is called a FLAT, b . For example, lowering the note D by one half-step gives you a Db.


The natural sign "♮" is used to neutralize or cancel a sharp or flat. We have not used the natural accidental in our construction of the Chromatic Scale, but it is important that you are aware of it and its function.


An accidental can be applied to any note, and this presents us with an interesting problem. Lets focus on the notes D and E.

When we construct the chromatic scale, we insert a note between D and E. Now, we have the option to either raise the pitch of the D to give us a D# or lower the pitch of the E to give us a Eb. No matter which method we use, the resulting note will be the same pitch, all be it with two possible names.

This leaves us with two distinct note names; D# and Eb. Again, these two notes are the same pitch. This occurrence is referred to as Enharmonics.

Double Sharps and Double Flats

Sometimes it is necessary to raise and or lower a note by a half-step (semitone), that has already been altered by an accidental. This occasion calls for the use of Double Sharps, x, and or Double Flats, bb.

To grasp this concept, your understanding of enharmonic equivalents is vital. For example:

  • Gb is the same pitch as F#
  • Gbb is the same pitch as F
  • Cx is the same pitch as D

Remain Flexible

With all enharmonic equivalents, the pitch of a note performed on the piano keyboard or your chosen instrument does not change, only the naming convention changes. 440 Hz remains 440 Hz whether you name is as A, Bbb or Gx. Pitch is constant. Names are flexible.

The Chromatic Scale

We have used examples thus far of musical notes in the order from which they appear in the alphabet. 'A' is the accepted and logical starting point when ordering anything alphabetically.

However, the note C is placed at the start of the Chromatic Scale and not A. There is of course a very good reason for A not being the starting point for our musical reference.

The letter C and the C scale have become the starting point,essentially as a result of the musical evolution. Familiarize yourself with the Chromatic Scale started with C.

The Chromatic Scale

The Chromatic Scale

Beginning with "C"

Explaining Cs alphabet position in music as the starting point requires us to delve into history, trying to make sense of the evolution that took place over many hundreds of years. Such an exploration is not necessary in your development as a musician or your continued understanding of music theory.

Throughout this course, you will come across many examples illustrating why it makes sense to begin with C. Where possible, we will highlight these examples for you.

Intervals - Half-steps and Whole-steps (Semitones and Tones)

As we said at the start of this lesson, an interval is simply the distance between any two notes. The first interval we will look at is the half-step. The half-step is always the closest note above or below a given note.

Using the Chromatic scale above as a guide, the note:

  • one half-step above C is C Sharp or D Flat (C#/Db)
  • one half-step above C#/Db is D

and so on through all notes of the Chromatic scale.

Remember, music is a series of repeating notes. When we reach the end of the Chromatic scale, we return to the beginning.

For example:

  • one half-step above B is C and one half-step below C is B

When searching for notes that are greater than one half-step above or below a given note, it helps to count out the number of steps required to arrive at a certain note.

For example, if we give the starting note E a value of zero:

One half-step above E is F

One halfstep above E is F

Four half-steps above E is G#/Eb

Four halfsteps above E is G#/Eb

Three half-steps below E is C#/Db

Four halfsteps above E is G#/Eb

The other interval we use to define a relationship between notes is the whole-step. The whole-step is equal to two half-steps. For example:

One whole-step above D is E

One whole-step above D is E

which is equivalent to:

Two half-steps above D is E

Two half-steps above D is E