The distance between two pitches. the distance between two pitches. The half-step is the smallest distance used in medieval music and a mixture of whole steps and half steps form the diatonic scales on which the music is based. From smallest to largest, the common intervals are unison (same sound), half step or whole step, third, fourth, tritone (which is to be avoided), fifth, sixth, seventh, and octave. See consonance and dissonance. <br><br>The distance between two notes<br><br>The relationship between two tones