A Special Note on Consonant Passing Tones and Neighbor Notes
Q: How can a passing tone or a neighbor note be consonant? Aren't
these types of dissonance?
A: Passing tones and neighbor notes are always dissonant relative
to more stable and essential structures. For instance, consider the
following phrase:

Note that every note in the bass and soprano lines is, in fact,
consonant in the literal sense -- each one is a member of the
governing triad at the specific moment we hear it. We could
understand mm. 3-4 of the phrase as having been created by the
following process:

