Discussion 10b - Error detection
Class discussion
Parallel perfect octaves (PP8)
- What causes this part-writing error?
- Both tones in our example are the leading tone of I–we have doubled thirds!
- Why is this bad?
- Lack of voice independency. A bunch of parallel motion can cause voices to bleed together, and then when they separate again it can be jarring to the overall texture
- If you were going to fix this, how would you do it?
- Have soprano sing a D in the first note of the second measure? (techincally yes, but it makes a jumpier melody which isn’t ideal)
- In the same place, change the tenor to a D instead of the soprano?
- Double the G in the lower two voices?
- Have soprano sing a D on the second and third chords?
- BASICALLY: fixing the errors is never as simple as you want it, and there’s a bunch of different ways to do it. Fixing them can be…trial and error :)
Parallel perfect fifths (PP5)
- Still considered a PP5 even in distant voices?
- Yes! Any of these movement errors can happen between any 2 voices
Contrary perfect fifths and octaves (CP5, CP8)
- Usually happens when trying to fix a parallel movement error by moving one voice an octave down. It isn’t ideal to sing and usually creates spacing errors as a result
- Red flag: if there’s a HUGE leap in one of the voices, there’s probably a contrary P5 or P8
Unacceptable unequal fifths (UU5)
- movement from a d5 to a P5
- must involve the bass
- Red flag: tendency tones not resolving the way they’re supposed to
- Ex: in C, B and F resolving to C and G. F is the seventh of a G7 chord and is supposed to resolve downward by step to the third of the next chord, but it went up to G instead.
- There is no octaves version of this one, fifths only
Unacceptable similar fifths and octaves (US5, US8)
- The most restrictve of these movement errors, so if you look for the specifics it will be easy to find!
- Can only happen in the soprano and bass
- Red flag: Skip of a third or more in the soprano voice + similar motion in soprano and bass
- Second interval must be a P5 or P8. What matters is what interval it lands on, not what it starts on