Music Theory for the 21st-Century Classroom

There is one general rule for voice leading any seventh chord: resolve the 7th of the chord down by step. All other voices should move smoothly to the nearest chord tone in a voicing containing the appropriate doubling.

The one exception to this is in the progression $\text{I}$–${\text{V}}_3^4$–${\text{I}}^6$, which closes the theme of the first movement of Mozart’s Piano Sonata K. 331.

In the example below, one can see that the 7th resolves up by step.

Notice that parallel fifths occur in this progression because of the upward resolution of the 7th. These parallel fifths may have been deemed less objectionable because they consist of unequal fifths (where one of the fifths is in a case of parallel fifths is diminished).