Progressions with inversions – 2
The passing 6-4 chord
The 6-4 chord (second inversion with the fifth in the bass) is used only in particular situations,
unlike the 6 chord which can be used wherever it sounds good. In the last video we saw the V64 used
as a passing chord, when passing from i to V64 to i6.
A i64 can also be used as a passing chord between iv6 and iv, usually going down.
In D minor, the iv chord is G-Bb-D so iv6 has the Bb in the bass. To progress to the root iv chord we
can use the i64 chord, with the A in the bass as shown. This provides a smooth transition in the bass
moving down from Bb to A to G.
The pedal 6-4 chord
Here we hold the bass and tenor notes on the D while moving the top two voices. The term 'pedal'
comes out of older organ music, where the bass (played on the pedals) is held while the upper
voices add decoration. The pedal 6-4 is used most often with a i-iv-i progression as seen here.
The cadential 6-4 chord
When we have a V-i cadence at the end of a phrase, we can move the V over and precede it with a
i64, known as a cadential 6-4 chord. This serves as a decoration of the V.
The first 2 bars show an unadorned cadence from V to i. Bar 3 shows the addition of a cadential i64
chord as an ornament. The tenor and bass are common tones with the V, and the voice leading in the
alto and soprano goes by a single step to the V.
A cadential i64 should always be at least as long as the V which it precedes.
In bar 1, the i64 is shorter that its following V, so this should be corrected to either of the next two
examples. In bar 4, the cadential i64 is the same length as the V, while in bar 7 it's longer, which is
also acceptable.
The i-iv6-V7-i progression
A variant on the i-iv-V-i progression uses a iv6, as shown:
The V42 chord
We can use a V7 chord with the seventh in the bass, thus making it a V42 chord, as part of a
progression from V to i6. The only note we've changed in the original V chord is the bass, from the
root (A) to the seventh (G). Obviously, this sort of progression can be done only with a seventh
chord, since we need the seventh as part of the chord.
Recall that the two tendency tones are the leading tone (C# here) and the fourth scale degree (G),
and that the leading tone tends to the tonic while the fourth degree tends to the third (F). When a
tendency tone is in an outer voice, it is exposed so needs to be voice led properly. For this reason,
the V42 almost always resolves to the i6; the G in the bass must resolve to the F, which puts the i in
first inversion.