Half steps and whole steps (semitones and tones)
A half step (semitone) is the smallest distance between two notes in Western music: from one piano key to the very next key, black or white. A whole step (whole tone) is two half steps, skipping one key. Major scales are built from a pattern of whole and half steps.
Half steps and whole steps measure the distance between notes. They are the units used to build scales, chords and intervals, so almost every other topic in music theory rests on them. Fortunately the idea is easy to see on a piano. This page explains both, shows them on the keys and on the staff, and gives you the pattern of the major scale.
What is a half step?
A half step is the distance from one key on the piano to the next key, whether that key is black or white. From C to C♯ is a half step, and so is C♯ to D, and E to F. In Britain this distance is called a semitone. It is the smallest step used in most Western music. On a guitar, a half step is one fret.
What is a whole step?
A whole step is two half steps. On the piano, it skips one key. From C to D is a whole step, because C♯ lies between them. From E to F♯ is a whole step too. In Britain a whole step is called a tone. On a guitar, it is two frets.
How do I find half steps and whole steps on the keyboard?
Just count the keys, black and white, between the two notes. If the notes are neighbors, they are a half step apart. If there is exactly one key between them, they are a whole step. White keys have a black key between them, except for the pairs E and F, and B and C. Those two pairs are half steps even though both keys are white. This is the key to reading steps: look at the keyboard first and let the pattern show you.
| Notes | Distance | Why |
|---|---|---|
| C to C♯ | Half step | Neighboring keys |
| C to D | Whole step | C♯ lies between |
| E to F | Half step | No black key between |
| F to G | Whole step | F♯ lies between |
| B to C | Half step | No black key between |
| A to B | Whole step | A♯ lies between |
How are steps written on the staff?
On the staff, a half step can look like a one-step move, for example E to F, or it can need an accidental, for example F to F♯. A whole step may look like a skip, such as C to D with the line moving up one position, but a half step may look like the same size, for example E to F. This is why the staff alone can't show the size of a step: you also need the key and the accidentals. The sharps and flats page explains the signs that change the size.
What is the major scale pattern?
A major scale is built from a fixed pattern of whole steps (W) and half steps (H): W W H W W W H. Start on any note and follow this pattern, and you have a major scale. In C major the half steps fall between E and F and between B and C, which are the places with no black key. The major scales page lists the scale in every key, and key signatures shows how the sharps and flats come from this pattern.
How many half steps are in an octave?
There are 12 half steps in an octave, which is why there are 12 different notes before the pattern repeats. Six whole steps also fill an octave. The chromatic scale goes through all 12 notes in half steps. Larger distances, called intervals, are named by how many steps they cover. A half step is also called a minor second, and a whole step is a major second.
- Find the first note on the keyboard.
- Count the keys, black and white, up to the second note.
- One key forward is a half step. Two keys forward is a whole step.
- Check the E to F and B to C pairs, which have no black key.
Memory trick: The two white-key half steps are E to F and B to C. Learn these and the rest follows: all other neighboring white keys are a whole step apart.
Practice by playing a major scale slowly and saying W or H for each step. The pattern will begin to feel familiar, and you will start to hear the small shift of a half step against the larger shift of a whole step.
Check yourself
1. How many half steps are in a whole step?
Answer: Two. A whole step is two half steps.
2. Which pair of white keys is a half step apart?
Answer: E and F. There is no black key between E and F.
3. What is the whole step pattern of a major scale?
Answer: W W H W W W H. The major scale follows W W H W W W H.
4. How many half steps are in an octave?
Answer: 12. An octave contains 12 half steps.
5. What is the distance between these two notes?
Answer: Half step. B to C is a half step, with no black key between.