# The chromatic scale

*Module 1 · Lesson 4: Notes and the fretboard · BazzLow*

> Know the twelve notes in order and see that each fret is the next one.

Before this lesson: [1.3 Sharps, flats and enharmonic notes](https://bazzlow.com/en/notes-and-fretboard/sharps-flats-enharmonics/)

Put the seven natural notes and the five notes in between together, and you have every note there is. This lesson puts them in order.

## Twelve notes

Seven natural notes plus five in-between notes make **12 different pitches**. Played in order, one half step at a time, they form the **chromatic scale**:

C · C♯/D♭ · D · D♯/E♭ · E · F · F♯/G♭ · G · G♯/A♭ · A · A♯/B♭ · B · (C)

All music in the Western tradition uses only these 12 notes, repeated in different octaves. Each of the twelve, whatever its octave, is called a **pitch class**: every C on your bass, low or high, belongs to the pitch class C.

## Every fret is the next note

On the bass, every fret of a string gives the next note of the chromatic scale. After 12 frets, the string’s own note comes back, one octave higher.

> **Diagram:** The E string, frets 0–12, every note, with sharps: E F F♯ G G♯ A A♯ B C C♯ D D♯ E.

> **Diagram:** The same string with flats: E F G♭ G A♭ A B♭ B C D♭ D E♭ E.

A common writing habit: going up, the in-between notes are written as sharps; going down, as flats. This is a convention that makes music easier to read, not a rule of theory.

## Equal temperament

Modern instruments use **equal temperament**: the octave is divided into 12 equal half steps. Each fret raises the frequency by the same ratio, the twelfth root of 2, which is about 1.0595.

Because each step is a ratio and not a fixed length, the frets get closer together as you move towards the body. Look at your bass: the gap between frets 1 and 2 is clearly wider than the gap between frets 11 and 12.

## Try it

Play the chromatic scale on the E string from fret 0 to fret 12 and back, saying each name: sharps on the way up, flats on the way down. Then do the same starting from the open A string.

## New terms

- chromatic scale
- pitch class
- equal temperament

Page: https://bazzlow.com/en/notes-and-fretboard/chromatic-scale/