Twelve-note collection moving exclusively by semitones; spans the octave.
Chromatic Scale
The Chromatic Scale includes all twelve pitches within the octave, each a semitone apart.
It’s not tonal in itself but functions as the complete set of available notes in Western equal temperament.
Composers and improvisers use it to connect melodic ideas, create tension, or color passing motion.
Formula:
All consecutive semitones — no skipped degrees.
Example – C Chromatic Scale:
C C♯ D D♯ E F F♯ G G♯ A A♯ B C
| Degree Count | Interval | Notes (C example) | 
|---|---|---|
| 1 | Unison | C | 
| +1 | Minor 2nd | C♯ | 
| +2 | Major 2nd | D | 
| +3 | Minor 3rd | D♯ | 
| +4 | Major 3rd | E | 
| +5 | Perfect 4th | F | 
| +6 | Tritone | F♯ | 
| +7 | Perfect 5th | G | 
| +8 | Minor 6th | G♯ | 
| +9 | Major 6th | A | 
| +10 | Minor 7th | A♯ | 
| +11 | Major 7th | B | 
| +12 | Octave | C | 
Usage:
- Melodic connection: fills gaps between diatonic tones.
 - Jazz and classical: adds tension and color through chromatic approach notes or runs.
 - Guitar & bass: used for slides, fills, and connecting scale tones (e.g., jazz walking bass lines).
 
While the Chromatic Scale itself isn’t tonal, it provides the raw material from which all diatonic, modal, and blues systems are derived.