In Western music, a semitone is the smallest interval between two musical notes. Two semitones are equal to one tone.
semitone in British English
(ˈsɛmɪˌtəʊn)
noun
an interval corresponding to a frequency difference of 100 cents as measured in the system of equal temperament, and denoting the pitch difference between certain adjacent degrees of the diatonic scale (diatonic semitone) or between one note and its sharpened or flattened equivalent (chromatic semitone); minor second
Also called (US and Canadian): half step. Compare whole tone
Derived forms
semitonic (ˌsɛmɪˈtɒnɪk)
adjective
semitonally (ˌsemiˈtonally)
adverb
semitone in American English
(ˈsɛmɪˌtoʊn)
noun
Music
the difference in pitch between any two immediately adjacent keys on the piano; half of a whole tone