A chromatic scale is a musical scale that includes all twelve notes available in Western music before the pattern repeats at a higher or lower pitch. If you've ever seen a piano keyboard, the chromatic scale uses every single key, both white and black, as you move from one note to the same note an octave higher or lower.

Most songs use a regular scale with seven or eight notes (like C, D, E, F, G, A, B, C), but the chromatic scale squeezes in all the notes in between, giving you C, C-sharp, D, D-sharp, E, F, F-sharp, and so on.

Composers use chromatic scales to create tension, suspense, or unusual moods in their music. You might hear chromatic passages in spooky movie soundtracks or in jazz music. When you play every key on a piano keyboard in order, you're playing a chromatic scale. It sounds quite different from the familiar “do-re-mi-fa-sol-la-ti-do” because it includes all those extra notes that give music its full rainbow of possible sounds.