Semitone

Uncommon card · No. 184696

In Western music theory, a semitone (also called a half step or half tone) is one of the two parts into which a whole tone is divided. Semitones are the smallest intervals commonly harmonically and melodically used in Western music, and are among the most dissonant intervals when sounded harmonically. A sequence of twelve semitones forms a chromatic scale, which informs the layout of many fixed-pitch instruments. For example, C is adjacent to D♭ on a keyboard, so the interval between them is a semitone. In musical notation, two types of semitones are distinguished. A diatonic semitone, or minor second, arises between two notes encompassing different staff positions, e.g. from C to D♭. A chromatic semitone, or augmented unison, arises between two notes at the same staff position, e.g. from D♭ to D♮. The sum of these two intervals, the interval from C to D, is a whole tone, or major second. The modern tuning system of 12-tone equal temperament divides the octave into twelve equal semitones...

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