(musicTheory2) Lecture Notes: Ch. 19, other seventh chords

• another choice to harmonize scale-degree 3-2-1 descents at cadences, but unlike the cadential 6-4 can be on a strong or weak beat.
  • The third of the iv7 must leap down to double the fifth of the V chord to avoid parallel fifths.
• can be part of V – IV6-5 – V6-5 – I progression (scale degrees 5 – 6 – 7 – 8 in bass).
• IV4-2 can go to ii7 or vii°6

Tonic seventh (I7 and i7):

• destabilizes tonic (can’t be used as target chord of cadence)
• often sets up a descending circle of fifths sequence.
• I – I6-5 – IV (I6-5 instead of I6)
• I – I4-2 – IV6 (bass descends 1 – 7 – 6; leading in bass does not resolve)