Seconds (music)

In Western music theory, a semitone (also called a half step or half tone) is one of two parts into which a whole tone is divided. Semitones appear as the smallest steps in chromatic scales (which divide the octave into twelve semitones), arising on keyboards between the pitches of two adjacent keys. For example, C is adjacent to D; the interval between them is a semitone. Semitones are among the most dissonant intervals when sounded harmonically.

musical interval spanning nine staff positions

musical interval

musical interval

musical interval of less than one semitone spanning two staff positions