Semitones and tones (also called Half and Whole Steps) are that concept of music theory that sooner or later you have to learn in order to make progress with your musical instrument (guitar, ukulele, piano, etc).
And the sooner you understand them the better. Therefore, in this post I will explain these concepts to you in the clearest possible way.
What is a half step in music (semitone)?
Let’s start with the basics, a half step or semitone is the smallest distance in pitch that exists between two notes in the musical system (western music). In other words, a semitone is the smallest distance that exists between 2 musical notes.
For example, if we look at the semitone chart below we have that between C and C# there is a semitone. On the other hand, between C and D there are two semitones (or one tone):
The important thing you need to know is that there are natural notes separated by whole steps and natural notes separated by half steps. The only natural musical notes separated by semitones are the E – F and B – C.
In addition, and as an important fact, the distance between C and the following C is 12 semitones or 6 tones:
By the way, a half step is also called half tone so you may find it as well when reading about this concept.
Let’s apply this concept to our musical instrument.
On a piano a half step would be the distance between a key and the nest one.
If you look at the image above you will find that sometimes 2 white keys have a black key between them and sometimes they do not.
Why is that?
This is because between E and F or B and C there is a distance of a half tone, but the distance between the rest of the notes is one tone.
How do we represent a semitone on the guitar?
Very easy, if you want to play a note that is one semitone higher in pitch than your current note, you simply move your finger to the right fret (towards the bridge of the guitar).
And likewise, if you want to a note that is one semitone lower in pitch than your current note, you move your finger one fret to the left (towards the headstock).
What is a whole step in music (tone)?
As we have already said in the previous section, a tone is the sum of two semitones, that is, a tone is equivalent to 2 semitones (or 2 half tone).
For example, from C to D there are two semitones or one tone. Similarly, from C to E there are four semitones or two tones.
And this concept is very important because with the tones and semitones we can draw the different types of musical scales. For example, the major scale has the following pattern of whole and half steps:
Once you have understood the semitone and tone definition, let’s see how we represent a whole step on the guitar.
And this is very intuitive because if a semitone was a fret, a tone is 2 frets:
Shaps and Flats
Now that you master the idea of tones and semitones we can go a little further and learn the possible music alterations that can be made to the semitones: the flats and sharps.
The sharp (#) is a symbol that makes the note one semitone higher in pitch. On the guitar it would be the right fret, so if we are playing the G note, the next fret would be G sharp (G#):
The flat (♭) is a symbol that makes the note a semitone lower in pitch. On the guitar it would be the left fret, so if we are playing the G note, the fret before would be G flat (G♭):
Types of Semitones
Before finishing this article let’s see the different types of semitones that exist in music:
A diatonic semitone is a half step that exists between two notes with different names. For example, there is a diatonic semitone between E and F, or between B and C.
A chromatic semitone is a half step that exists between two notes with the same name, one natural and one altered. For example, a chromatic semitone exists between G and G♭, or between D and D#.
Tones and Semitones on the musical staff
Finally, let’s see how we can represent a half steps on the staff.
And this is actually very simple, since we only need to add the necessary symbol to the note.
For example, imagine that you want to transform B into B♭, you only have to place the flat symbol to the left. On the other hand, if you want to make it sharp (#), just place the flat symbol to the left of the musical note.
And with this we have finished the lesson of tones and semitones on the guitar.