In another post I learned that an 8th note chordal skip can produce consecutive parallel intervals even when the parallel interval happens off the beat. But what about a 16th note descending line like this one? Would this be allowed in a 4 part harmony exercise? You see the B on the last 16th of beat 2 make a parallel octave with the tenor and to my ears it is not audible unless I play it super slowly.
Yes, it unfortunately doesn't matter the note value; no matter how fast or how slow, two consecutive intervals of a perfect octave (or perfect fifth) between the same two voices results in unstylistic ("incorrect") voice leading.
There are multiples solutions to something like this, so to share just a few:
- If the two affected voices can be solved with a voice exchange, pursue that option. On beat 1, you may want a chordal skip of B–D♯ in the bass, but this creates parallel octaves with the alto. As such, change the alto to eighth notes of D♯–B, creating a voice exchange between alto and bass.
- Try another chordal leap in the voice that you changed. Here, your bass could also arpeggiate down to G♯ in beat 2 to prevent any voice-leading issues.
- Create a new chordal skip in the other voice that creates the parallels. You've changed the bass, which created parallels with the tenor. So now embellish the tenor to have B–G♯ to rid of these parallels.
- Consider other embellishment types. In addition to passing tones and chordal skips, what about neighbor tones, suspensions, appoggiaturas, etc.?
Strictly speaking no, but occasionally you get away with it. In this case there are more problems than this one. The notes you have there are A#,C#,E, which is characteristic for the dominant on F#. So doubling the A# has some sort of doubling-the-third character. This quite problematic, as this leading tone demands a resolution into the tonic, thus this would require parallel octaves. Also having a diminished chord like this is not really optimal.
Rather you might want to have the tenor go into the F#, filling up the F# dominant chord.