Half Steps and Whole Steps

You can now read the rows of the piano roll. What's left is measuring the gap between two of them, and that skill will serve you for the rest of the course. Scales, chords and intervals are nothing more than distances between notes. The good news: on a grid, you count those distances like squares.

One row is a half step

A half step, which most software and many producers call a semitone, is the distance from one row to the row just above it, whatever the color of the keys. It's the smallest gap between two neighboring keys, and the one every piano roll is built on. An octave contains twelve of them, since there are twelve rows before you land on the same note again.

A whole step, also called a tone, equals two half steps: you skip one row. Look at the figure: in the first bar, the melody goes up a single row; in the second, it goes up two.

Between C and the black key just above it, there's a half step; between C and D, there's a whole step. Keep this picture in mind: the half step is the smallest possible move on the grid, and the whole step is two of them.

Counting distances on the grid

To measure the distance between two notes, count the rows you cross going from the first to the second, without counting the row you start on. From C4 to E4, for example, you pass the black key above C, then D, then the next black key, and you arrive on E: four rows, so four semitones, that is, two whole steps.

With this method, the octave is easy to check: from C4 to C5, you cross twelve rows, so twelve semitones, or six whole steps. You don't need any formula; just count without rushing.

The half step that clashes

You don't just see a half step, you hear it, and in a very particular way. Played together, two sounds a half step apart rub against each other: you hear a kind of grinding, a fast wobble. Played one after the other, on the other hand, they make a very gentle slide, almost a sigh. Listen, then compare with a whole step.

You heard it: the whole step rubs a little too, but much less than the half step. That friction isn't a mistake in itself, and composers use it to build tension, as we'll see in the lesson on consonance and dissonance. But when it happens by accident, it gives that wrong-note feeling that makes a track “sound amateur.” The typical case is a melody note that lands a half step away from a note held by the bass or a pad, and clashes for its whole length.

E to F and B to C: half steps with no black key

Look at the keyboard. Between most neighboring white keys, there's a black key: from C to D, from D to E, from F to G, from G to A and from A to B, so each of those is a whole step. But in two places there's no black key: between E and F, and between B and C. There, two neighboring white keys are only a half step apart.

On the piano roll, you spot them as two light rows right next to each other. This has an important consequence: the white keys aren't evenly spaced. Going up from C to the next C, you get whole, whole, half, whole, whole, whole, half. Keep this pattern in mind; it will come back when we build the major scale.

Transposing: moving without bending

To transpose means to move every note of a motif by the same number of semitones, up or down. The shape of the motif doesn't change: the distances between the notes stay the same, and your ear recognizes the same melody, just higher or lower. In the figure, the second bar repeats the first, three rows higher.

Notice that the transposed version uses black keys even though the original had none. That's normal: you count rows, not colors. The trap would be to move each note to the next white key. Try it with the start of the motif, D, F, E: moving each note up one white key gives E, G, F. But D has gone up two semitones, F two as well, and E only one, because of the half step from E to F. The motif is bent out of shape, and your ear hears it right away.

You've been handling black keys without being able to name them yet. That's exactly what the next lesson covers: sharps, flats, and notes with two names.