Semitone

Music Theory

A semitone (or half step) is the smallest pitch distance in Western music. On the ukulele, moving one fret up or down equals one semitone. Two semitones make a whole tone (whole step). The entire chromatic scale is a series of 12 semitones before the pattern repeats an octave higher.

Understanding semitones is key to transposing songs. To raise a song by one semitone, shift every chord up by one (C→C♯, G→G♯, Am→A♯m). To lower it by two semitones, shift everything down by two (C→B♭, G→F, Am→Gm).

Semitones also define chord quality. A major chord has 4 semitones between its root and third, while a minor chord has only 3. This single-semitone difference is what makes major chords sound "happy" and minor chords sound "sad."