Half Steps, Whole Steps and Accidentals

Once you can name the notes, the next question is how far apart they are. The piano measures distance in small, even steps. This lesson is about the two smallest ones, the half step and the whole step, and about the symbols that shift a note up or down: accidentals.

Half steps and whole steps

A half step (also called a semitone) is the distance from one key to the very next key, with nothing in between. That next key can be white or black, so count every key you pass. The half step is the smallest distance on the piano. A whole step (a tone) is simply two half steps stacked together, so you skip one key to land on the next.

Play this below. Pick any key, then play the key immediately next to it: that is a half step. Now move two keys over: that is a whole step. Listen to how much tighter the half step sounds.

The black keys have two names

Look at the black keys. Each one sits between two white keys, and it can be named from either side. That is what accidentals do:

• A sharp (♯) raises a note by a half step.
• A flat (♭) lowers a note by a half step.
• A natural (♮) cancels a sharp or flat and returns to the plain white key.

So the black key between C and D is a half step above C, making it C♯, and also a half step below D, making it D♭. It is one key with two names. Two names for the same pitch are called enharmonic.

The gaps with no black key

The black keys are not evenly spaced, and that is the key to understanding the keyboard. Between two white keys there is usually a black key, so those white keys are a whole step apart. But at two places the white keys are only a half step apart, with no black key between them: E to F and B to C. Find those pairs and play them; they sound as close as any black-key half step.

A half step is one key to the next, always. A whole step is two half steps. Everything larger in music is built by counting these small distances, so it is worth playing them until the sound is familiar.