Cadence in Haydn's String Quartet in G, Op. 54, No 1, i, 1-13

I'm studying with a book called "Analyzing Classical Form" and it says that the cadence in this piece starts it's cadence on the 2nd half of m 10 but that's a III(5) and I'm so confused.

If I analyzed it correctly it goes like this:

m10.5: III(5)

m11: IV (Csus#4 but I think it can be described as the IV)

m11.5: II

m12: I(64)

m12.375: I(764)

m12.5: V(7) Repeated for 3 times (eights)

m12.875: vii°(9)

m13: I

Can anyone explain to me why the cadence starts on m10.5?

1. Why does this Cadence start on a III? I've heard people calling it everything from Tonic to substitute Dominant so I'm confused.

2. Why does it go D-Pd-T-D-D-T (Pd = pre-dominant)

If the normal structure is T-PD-D-T for a perfect authentic cadence does that mean that I could insert (in common time and 1 chord per bar) 2 Dominants with half a bar of length for the D?

PS. At this point even my confusion is confused so don't be sacred to write a long answer, it'd help me a lot. Just explaining from ground up why for God's sake this is a complete cadence (I get that eveything is in there but the order and the amount of chords is what confuses me)

• Where on the website does it say that the cadence starts on Measure 10? For that matter, where are the questions for that section? I see 4 answers in the link, but no questions. Commented Jan 8, 2018 at 23:31
• The questions are in the book, question 4 is "Where does the cadential progression begin? Is it complete or incomplete?" My bad, I forgot to refer to them in the main question, sry Commented Jan 8, 2018 at 23:35
• What you describe as I(64) is really V with a suspension 6-5 and 4-3. This is a cadential six-four, which is an idiomatic way to prepare a cadence (although in this example the voices get exchanged before they get resolved). This is not a tonic.
– Remy
Commented Jan 9, 2018 at 0:16
• Thanks a lot, that was so helpful :). One more question: If I see this correctly it's iii-IV-ii-V-I a.k.a. T-Pd-Pd-D-T is that correct? I'm just not sure but I think that in this case the iii is counts as a tonic as it doesn't substitute for a dominant, right? Also do the two Pds count as one? That would make it a typical T-PD-D-T. Commented Jan 9, 2018 at 1:14
• The second half of measure 10 is a I⁶, not a iii. The next measure indeed contains two slightly different harmonies (IV ii⁶) that together form the PD; this is a common expansion of the predominant sometimes referred to as the IV-ii-complex.
– Remy
Commented Jan 9, 2018 at 1:57

What you describe as I(64) is really a dominant V with a suspension 6-5 and 4-3. This is a cadential six four, which is an idiomatic way to prepare a cadence. This is not a tonic. In this example, the voices get exchanged before they get resolved.

The idea of embellishing the dominant through some sort of suspension is extremely common in the common practice period. Here are some examples (you should listen to a little bit before the linked excerpts as well to get an idea of the tonality):

• Händel, Zadok the Priest, cadence at the end of the orchestral introduction. This pattern is sometimes called a double cadence (see e.g. this website), and consists of a held V in the bass with a four chord embellishment happening on top. Very typical of baroque and (early) classical.
• Tchaikovsky, Overture 1812, final cadence before the coda. This only uses the 4-3 suspension.
• Mahler, Symphony no. 1, final cadence in the last movement. This uses an extensive 6-5, 4-3 suspension, where the final resolution only arrives a full 16 measures (20 seconds) later. This type of extended cadential embellishment is common in the romantic period (although they'll also make you wait a bit for the dominant to arrive in the first place...).

Eventually you wear learn to recognise these quickly, both aurally and visually. The tonic-sounding chord but with a 5 in the bass is often a signifier of a cadence coming up.

The two predominants IV and ii⁶ are often combined to form a predominant expansion. This is sometimes called the IV-ii complex. In terms of voice leading, the only thing you need to do is move scale degree 1 (G in this piece) to scale degree 2 (A).

If the ii⁶ moves directly to a dominant V (without cadential six four), the A can be viewed as an anticipation of the A in the V harmony. This can help avoid parallel fifths, which is probably how the IV-ii complex originally came about.

I could probably find good examples from different periods of the IV-ii complex as well, but it's not nearly as important to know about as the cadential embellishments linked to above.

• The reason I added some examples is mostly to encourage you to find examples in the pieces you love. Preferably by ear, without referring to the score.
– Remy
Commented Jan 9, 2018 at 4:47