Playing Half Steps and Whole Steps on Piano or Keyboard
In Western music, an octave is broken up into 12 tones called half steps, or semitones. To play the piano or keyboard, you should know that a musical scale contains seven notes, meaning that some of the distance between notes in a scale spans one half step, and some spans at least two half steps. In other words, some half steps are skipped when building scales.
When musicians talk about the notes A, B, C, D, E, F, and G, they mean the natural notes — specifically, the notes that correspond to the white keys on a keyboard. The white keys of the keyboard were assigned the natural letter notes, which turn out to be the notes of the C major scale, beginning with C.
However, because you’re dealing with a musical vocabulary made up of 12 half steps (or semitones), the keyboard also has five black keys, repeated over and over, which represent the semitones that are skipped in the C scale. The black keys were added much later than the original white keys in order to help build more perfect musical scales on the piano.
Moving a whole step on the piano means you move two half steps from your starting position. Half steps and whole steps are called intervals. Knowing the difference between whole steps and half steps is important when working with the patterns used to build scales and chords.
You also employ half steps when you come across an accidental, a notation used to raise or lower a natural note pitch. So when a note is sharped, you add a half step to the note; when a note is flatted, you remove a half step from the note.
Working with half steps
In Western musical notation, the smallest difference between two pitches is the half step, or semitone. Using the piano keyboard as a reference, if you pick a key, play it, and then play the key that’s right next to it (on the left or right) whether that key is black or white, you’ve moved one half step in pitch.
Because musical pitch is actually a continuous spectrum (think about a trombone sliding up the scale), many other microtonal sounds actually exist between consecutive half steps. But Western musical notation only recognizes the division of pitch into half steps. In contrast, many Eastern instruments, particularly sitars and fretless stringed instruments, use quarter tones. Quarter tones are pitches located halfway between each half step.
If you start out playing an E on the piano, a half step to the left brings you to E ♭(E flat), which could also be called D ♯ (D sharp). A half step to the right lands you on E ♯, which is more commonly known as F, or F ♮(F natural).
When a musician refers to a note being flatted, you know you need to move one half step to the left of that natural note; if it’s being sharped, you know to move one half step to the right.
Every black key on a piano has two names: It can be referred to as the flat of the white key on its right or the sharp of the white key on its left. For example, E flat and D sharp may be written as different notes, but they have the same pitch, or sound. Notes with the same pitch are referred to as enharmonic.
Taking whole steps
Following the logic that a half step on the piano is one key away from the starting point, it only makes sense that a whole step would be two keys or frets away from the starting point.
Say, for example, that you start on E on the keyboard. One whole step to the left of E would be D.
Meanwhile, one whole step to the right of E would be F sharp.
The distance between the consecutive white piano keys E and F, and B and C, equals a half step, whereas the distance between the remaining white keys (G-A, A-B, C-D, D-E, F-G) is a whole step. That’s because the piano is designed around the C scale.
Changing pitch with accidentals
Accidentals are notations used to raise or lower a natural note pitch on the staff by a half step. They apply to the note throughout a measure until you see another accidental. You can use these different types of accidentals:
Double sharp (X)
Double flat (♭ ♭)
A sharp is placed before a note to indicate that the note is a half step higher.
Here’s a sharped E (the enharmonic of F natural). E sharp is one half step up in pitch from E.
A flat does just the opposite of a sharp: It lowers the note by a half step.
Here’s a flatted E. E flat is one half step down in pitch from E.
Every once in a while, you’ll run into a double sharp or a double flat. The double sharp raises the natural note two half steps — or one whole step — whereas the double flat lowers the note two half steps, or one whole step.
Naturals: Cancelling sharps and flats
Last but not least is the natural.
When you see a natural sign next to a note, it means that any sharp or flat that’s already in effect is cancelled for the rest of the measure. In other words, you’re supposed to play the “natural” version of the note instead of whatever sharp or flat was in effect, even if it was a double sharp or double flat.