A semitone, or a half step, is the smallest interval (distance between two notes) used in the Western music tradition. On a piano you can see it as the step from one piano key to the very next.
But small does not mean insignificant! This little tiny interval is actually rather powerful.
Just think about how it is used in horror movies like “Jaws”, the famous theme with only two notes repeated a half step apart again and again, faster and faster…
The first motive in L. V. Beethoven's "Fur Elise" is also a repeated halfstep interval: E-Eb-E-Eb-E.
The easiest way to see how the pattern of tones and semi tones look like is to look at a piano keyboard. From each key of the piano to the very next there is a semi tone:
It will always be from a white key to the nearest black key or reversed, except in the place where there is no black key. Can you see where it is?
Right! Between E – F and B – C there is no black key, since they already are only a half step apart.
A scale consists of tones organized in a certain pattern. This pattern all depends on exactly how far it is from one tone to the next.
Many scales in the Western musical tradition are made from a combination of whole tones (or whole steps) and semi tones (or half steps).
But on a music staff you can't see where the semitones are hidden!
All notes are evenly spaced apart on the staff so it looks like they are all the same distance, but some are actually a half step apart and some a whole step… so how can we know?
Well, you have to memorize that between E- F and B - C there are always semitones.
Not so hard really. Here is a major scale starting from C. The half steps between E-F and B-C are marked with ^ :
Here is a treble staff filled with notes. The half steps have been marked out, always between E-F and B-C, up or down:
Here is a bass staff. Half steps again between E-F and B-C (I told you so!)
This time the steps are grouped two and two. Now it's your turn!
Can you see which intervals are a semi tone apart and which a whole tone?
Try first with the treble clef: (Hover for the answer.)
And here with the bass clef:
OK. Let’s make it harder!
Can you spot the semi tones here?
The power of semi tones! Listen to the semi tones starting each of these famous compositions: