Semitones

Part of speech: noun

Definitions

1. A specific interval in music that represents the smallest step within an octave, important in the creation of scales and harmonies
2. Distinct divisions of an octave in Western music theory, where each semitone represents a half step between notes in a chromatic scale
3. The fundamental unit of measurement in music that indicates the pitch difference between two adjacent keys on a piano keyboard

Etymology: "Semitones" is the plural of "semitone," a half step in the chromatic scale. The word is a straightforward compound: "semi-," from the Latin prefix meaning "half," joined to "tone." That "tone" is the older musical sense, borrowed into English from Latin "tonus," which came from Greek "tónos," meaning a stretch, tension, or pitch of a sound. The Latin prefix "semi-" is the same root that gives English "semicircle" and "semifinal," so a semitone is literally a half tone. The logic is that two adjacent notes, such as E and F or B and C, are separated by the smallest interval used in Western scales, which musicians measure as half of a whole tone. The plural simply adds "-s" to count these intervals, as when a piano keyboard is described as containing twelve semitones per octave.

Synonyms: half steps