Lessons with Matthaeus

Hi Máté,

Great - yeah in bar 18 there's an imperfect cadence. Well done about bars 19-20, that is right, the G is maintained in the bass, preventing a sense of cadence. Holding a bass note on like is called having a pedal, over which the harmonies can change (here resulting in a 6/4) chord. This bass pedal creates a sense of tension, (the music feels like it needs to go somewhere), and then we move into G major briefly, only to return to C shortly afterwards.

What I want you to notice here is how the insertion of the F# immediately suggests a feeling of modulation in this instance.

Look at the next example however (attached). What is going on at the cadences? Is there a modulation? (I've attached a midi for you to listen to)

OK, Matt, I give it a try:

Bach R.356 (D minor)

Bar1 ends with Dmin chord in first inverion (i6/3).
Bar2 starts with an A7 chord in 1st inversion followed by Dmin (V6/5 - i). After that there's an E7 in 1st inversion followed by A7 (7th added a bit later) and finally a Dmin (II6/5 - V7 - i).


Bach R.106 (A major)

Bar1: The first 3 chords are A, E6/3 and D6/3 (I - V6/3 - IV6/3). It seems to me that the fourth chord is some form of the tonic (I6/4 ?) or dominant (???), or vi in root position with a dissonant bass (I'm just guessing ).
Bar2: B7 in first inversion followed by E (7th added later in the tenor), and finally the E7 goes to A (II6/5 - V7 - I).


Conclusion:

The "II6/5 - V7 - I (i)" progression is used at cadences in both examples. I don't think it's a modulation since V7 is not a stable chord and cannot be a tonic.

Hi Máté,

Yes that's exactly right. (Don't worry about the chord on beat 4 of the second example - it's too complex to explain for now).

So what has happened is that Bach has made ii6/5 into a major chord. The reason he does this is because it leads better onto V7, because of the resolving tritone. It also gives him a chromatic bass-line (which makes things more interesting).

Another way to describe II6/5 is as V6/5 in the dominant. That means that Bach uses the dominant of the dominant to reach the dominant itself.

Every chord has its own dominant, and you can alter minor chords into major chords in order to make the most of circle of fifths relationship. Does this make sense? I'll get some examples up soon.

OK, I think I understand it. But is it possible use II6/5 in other inversions?

Ah yes of course it is, root position is fine, but II6/5 works much better because the bass line leads up to the dominant note chromatically. Also in general, ii6/5 - V7 -I is much more common than just ii7 - V7 - I, first inversion sounds better, and the seventh adds strength to that relationship. One reason I can think of for this is that it makes the V - I relationship clearer. II7 - V could be misconstrued by the ear as a perfect cadence, but II6/5 - V just sounds like it's leading up to a perfect cadence. Of course if you want to use II (with a major third) at other points in your piece that's fine, and it doesn't necessarily need to lead to perfect cadence. You could also use it to get I6/4 for example.

Hi Máté just to let you know I'm going to be really busy over the next month or so, but don't lose hope I will be back!

Matt