Chromatic also means "colored", so if you've ever heard anyone refer to notes being different colors. This scale is made up of all the colors or notes. (A, Bb, B, C, C#, D, D#, E, F, F#, G, G#, A).

The chromatic scale doesn't get much use as a harmonic or melodic scale. You will often see it in passages, like when the music stops and just the guitar plays a chromatic passage from one note to another. It's used alot in improv as well, cause it's sort of like the freedom scale. Very rarely used in it's entirity. Sometimes if you analyze a piece of music and you see alot of accidentals, you may think it's chromatic (yeah it's could be true), but usually it's just chord harmonization that is being used. This is using different scales over different chords instead of one scale over an entire chord progression. This will produce alot of accidentals but it is controlled, rather than being chromatic. Jazz and Blues primarily used this way of harmonization, but it is still used today.