Lesson 23: Tones, Semitones, Chromatic Semitones, Diatonic Semitones

Category: Lessons

We have already been dealing with tones and semitones in previous posts without even realizing it. A SEMITONE is the smallest distance between any two sounds used in Western music.  It is the smallest distance between any two adjacent keys on the piano, whether they be black and white, or white and white. We have already touched this concept when learning about sharps, flats, and accidentals.

A TONE (or WHOLE TONE) is equals to two semitones (in the same direction). Pick a note on the keyboard, now find the next semitone to right.  Move right one more semitone, and you’ve got a WHOLE TONE.  You can do the same thing in the opposite direction.

Now that we have fleshed out the intracacies of the Western concept of a semitone, we can delve a bit further.  A semitone comes in two “flavours”: chromatic and diatonic.  When a semitone contains two notes with the same letter name, it is called a CHROMATIC SEMITONE. See below for examples of chromatic semitones. As you can easily see, the notes of a chromatic semitone are the same, but one is altered with an accidental.


A diatonic semitone occurs when a semitone contains two notes with different letter names.  See below for examples.


A chromatic semitone can be manipulated to be a diatonic semitone and vice versa. Remember, that most notes can be referred to by different note names.  For example E# and F are the same note.  Take a look at the two intervals below.  They are equivalent, but one is a chromatic semitone, and the other is a diatonic semitone. Try to identify tones and semitones on the piano keyboard. The more you practice the easier it will become.  It is very important to grasp this concept fully, as it will form the foundation of many future lessons in musical theory.


Posted on June 13th, 2009 by sharlene


  1. poo Says:

    It was really helpful and i have gotten through theory real fast

    thx a lot

  2. Marilyn Says:

    I need more information on a diatonic semitone please. i.e. what is the diatonic semitone of B going up the scale. Isit Aflat?

    Thank you

  3. sharlene Says:

    Hi Marilyn,

    The diatonic semitone of B going up is C. The chromatic semitone of B going up is B#. Note that these are actually the same key on the keyboard, but look different in musical notation.

    Hope this helps,

  4. Lesson 29: Scales and Why We Need Them. Major scales, C major scale | Epianostudio Says:

    […] So, how do we construct a major scale? The major scale has a basic formula, no matter what note you are starting on. The basic formula is this: Tone-Tone-Semitone-Tone-Tone-Tone-Semitone. Uh, got it? If you don’t remember about tones and semitones, you can review them in Lesson 23: Tones, Semitones, Chromatic Semitones, Diatonic Semitones. […]

  5. Matthew Says:


  6. Sian Says:

    In the theory book by Mark Sarneki, Basic Level, the example musical notation for diatonic semitone IS EXACTLY the same as chromatic semitone. eg. both notes were written as G to G# and using the G on the 2nd staff line in treble clef.

    Is this correct?

  7. judy Says:


    how can i know when to write sharp or flat in exercises, because some time we write both sharp and flat? please help me

    thank you

  8. bob Says:

    It helped me ALOT in Rudiiments!

  9. Robert Says:

    A good way to remember chromatic and diatonic is that the word chromatic starts with ‘c’ and the word diatonic starts with ‘d’. Therefore ‘C’ to ‘C sharp’ is a ‘C’hromatic semitone, but ‘C’ to ‘D flat’ is a ‘D’iatonic semitone, hope that helps!

  10. Review of Major Scales and Major Key Signatures | Epianostudio Says:

    […] Remember that a tone is 2 steps on the piano, and a semitone is 1 step – or the smallest distance between any two notes on the piano. You can review tones and semitones here. […]

  11. Leonardo Says:

    Which clef am I looking at in this lesson? Treble or bass?

  12. Leonardo Says:

    ok I understand, it’s all treble clef

  13. Freya Says:

    I dont understand what a semitone is i need more information

  14. Janice Says:

    I don’t understand anything… agree with you Freya

  15. laren Says:

    i still dont understand this???????

  16. qi Says:

    what is a chromatic semitone

  17. qi Says:

    can you give more example

  18. Random Pianist Says:

    Whole Tones: C to B, F# to G#
    Diatonic Semies: Bb to C, D to Eb.
    Chromatic Semies: G to G#, F# to F.

  19. Herold Says:

    What would be a chromatic semitone above ‘a flat’?

  20. justin Says:

    What is a chromatic semi tone above b? B Sharpe?

  21. Piano Master Says:

    It’s b flat and b Justin

  22. Bob Says:

    Herold it would be the next white key under the flat.

  23. praise c Says:

    this is very educative.i wish to see more of this.

  24. Isora Says:

    Can anyone please tell me what is the diatonic semitone below c flat

  25. Person Says:

    This was not helpful at all. Now I’m even more confused and frustrated, i bate music theory so much fml I wanna kill myself.😡

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