Approaching dominant: $\text{IV}$, $\text{ii}^6$, $\text{ii}_5^6$

  • in major: $\text{IV}$, $\text{ii}^6$, $\text{ii}_5^6$ (fa-la-do, fa-la-re, fa-la-do-re)
  • in minor: $\text{iv}$, $\text{ii}^{\circ 6}$, $\text{ii}^{{\varnothing}_5^6}$ (re-fa-la, re-fa-si, re-fa-la-si)
  • serves as subdominant
  • leads to dominants such as $\text{V}/\text{V}^7/\text{vii}^{\circ 6}$

subdominants$-\text{V}$

subdominants$-\text{V}^7$

subdominants$-\text{V}_2^4/\text{V}^6/\text{vii}^{\circ 6}$ (inversions of dominants)

useful for cadence

move between subdominants

  • $\text{IV}-\text{ii}^6-\text{V}$: common
  • $\text{ii}^6-\text{IV}-\text{V}$: uncommon

voice leading

$\text{IV}$ and $\text{ii}^6-$ dominant

  • double root of $\text{IV}$
  • double $\hat{2}/\hat{4}$ of $\text{ii}^6$

careful with parallel 5th/8th when moving to V

to avoid parallel motion: upper voices and bass are better in contrary motion

$\text{ii}_5^6-$dominant

$\text{iv}/\text{ii}^{\circ6}/\text{ii}^{{\varnothing}_5^6}-$dominant

  • in minor, $\hat{6}$ is a tendency tone that pulls down
  • $\hat{6}$ should never go up
  • avoid doubling $\hat{6}$
  • raise $\hat{6}$ then they become $\text{IV}$, $\text{ii}^6$, $\text{ii}_5^6$, they can move up to leading tone

Approaching $\text{V}$: $\text{IV}^6, \text{IV}^7, \text{ii}, \text{ii}^7$

$\text{IV}^6$

  • $\text{IV}^6-\text{V}/\text{V}^7$ (root position or 1st inversion)
  • bass move stepwise
  • in minor key, $\text{iv}^6-\text{V}$ half cadence is common
  • called Phrygian cadence sound1 sound2
  • double any key of $\text{IV}^6$
  • should not double the bass of $\text{iv}^6$, because it’s a tendency tone (fa-la-re)
  • in minor, if the bass ascend to $\text{V}$, should raise $\hat{6}$ so $\text{iv}^6$ is turned into $\text{IV}^6$, to avoid the augmented second

root position $\text{ii}$

  • functions as subdominant
  • leads to $\text{V}-\text{V}^7$
  • in minor is diminished
  • minor $\text{ii}^{\circ}$ is less used than $\text{ii}^{\circ 6}$
  • should double the root
  • avoid parallel 5th and 8th in $\text{I}-\text{ii}^{\circ}$; upper voices and bass better in contrary motion

$\text{ii}^7$

  • usually in first inversion $\text{ii}_5^6$ (see earlier)
  • also in other inversions
  • when progressing to $\text{V}$, chordal 7th steps down

$\text{IV}^7$

  • usually in root or 1st inversion
  • chordal 7th must step down

alternating

  • $\text{ii}$ and $\text{IV}$ can move between root and first inversion
  • $\text{IV}-\text{ii}$ is more common than $\text{ii}-\text{IV}$
  • $\text{ii}/\text{IV}-\text{ii}^7/\text{IV}^7$ ok
  • $\text{ii}^7/\text{IV}^7-\text{ii}/\text{IV}$ bad because chordal 7th would not resolve properly

$\text{IV}-\text{I}/\text{I}^6$

  • no leading tone in $\text{IV}$
  • $\text{IV}-\text{I}$ is less strong than $\text{V}-\text{I}$
  • $\text{IV}$ embellishes $\text{I}$ in $\text{I}-\text{IV}-\text{I}$
  • one upper voice sustains on $\hat{1}$
  • could be used for melody line 343, 565
  • melody usually stays or step down
  • $\text{IV}$ must in root position
  • $\text{I}-\text{IV}^6-\text{I}$ is uncommon

plagal cadence