passing tone
A non-chord tone that fills the gap between two chord tones by stepwise motion
In Depth
A passing tone moves by step from one chord tone to another, passing through a dissonance on the way. It can be accented (falling on a strong beat) or unaccented (falling on a weak beat). Chromatic passing tones use half steps that do not belong to the prevailing scale. Passing tones are the most common type of non-chord tone and are fundamental to creating smooth, singable melodic lines. In counterpoint, they were among the first permitted dissonances.
In strict Renaissance counterpoint, unaccented passing tones were freely allowed, but accented passing tones required careful preparation and resolution.