How can I harmonize this cadence? V-I? It causes parallel octaves between bass and soprano
There is no way to write a V to I cadence with both chords in root position without creating parallel octaves with that melody.
So your options are to either:
- Put one of the chords in inversion. It's best to end on a root-position tonic chord, so I recommend putting the V chord in first inversion. The chordal third, E, will be in the bass. One way of doing this is to have
C C D Eeighth notes in the bass as
E E D Cis happening in the melody. This creates a nice "voice exchange" between the outer voices.
- Or, you could rewrite the melody so that it doesn't end with C to F. That way you could have a V to I cadence with both chords in root position.