# How to analyze mm. 5-8 in the first movement of Beethoven Piano Sonata No. 8

Everything makes sense until mm. 5. It looks like it moves from c minor to Eb major.

Suppose we're in Eb major starting at mm. 5

From the end of mm. 5 to the very beginning of mm. 6, it's a `vii°7/vi` in Eb. It cannot be `vii°7` because the root is B. It can't be `CT°7` of the next chord because the root of the next chord is not in it.

Then it moves to the `V7` chord. But it's not used functionally because it never resolves.

Next, it becomes even more interesting. It goes to `vii°42/D` and `V42/D`. And it resolves to `D6` in mm. 7.

Finally, it goes to `vii` and `V` of c minor in mm. 8-9 (simplified a bit here).

mm. 5 is probably never in Eb

That D chord in mm. 7 is probably not in Eb major. It makes more sense to be a `V/V` in c minor.

If we work backward, that `vii°7/vi` in Eb should be `vii°7` in c. It came from `iv42` in c (instead of `ii42` in Eb). Beethoven just used that long dominant chord in mm. 4 to tonicize to III of c minor.

But what is that unresolved dominant in mm. 6?

It probably makes sense in the context of a sequence. The voice leading takes precedence of its function. And it sounds surprising. I guess there can be a better explanation here. I'm curious to hear what people think.

Conclusion

Thanks @Aaron for the response. I think everything makes more sense taking into account the enharmonic spelling. So this is what I have. Everything is in c minor.

measure 5

It starts on `III` of c minor. Goes to `iv42` on beat 3.

On beat 4, it moves from `CT°7` -> `iv64` -> `vii°7/III`.

measure 6

It moves from `vii°7/III` to `V7/III` on beat 2.

In the rest of the measure, instead of resolving the `V7`, it moves on from `vii°42/V/V` -> `V42/V/V` -> `vii°43/V/V`.

measure 7-8

It resolves that `vii°43/V/V` to `V6/V`.

Starting from beat 3 until the end of beat 2 on measure 8, it goes through inversions of `vii°42` and lands on `V7` in beat 3.

Finally, it moves from `V7` -> `iv7` -> `V7`.

At a high level

If we ignore those fancy applied chords (`vii` -> `V` on those tonicized centers), this is what happens from measure 5-8 (ignoring the inversions).

`III` -> `iv` -> `V/III` (or `VII`, unresolved) -> `V/V` -> `V` -> `iv` -> `V` -> `i`

I still find that unresolved dominant in measure 6 very interesting. It's Beethoven telling you "Hey, think I'll resolve to Eb? Guess where I go next!". In terms of listening, it creates a strong sense of searching.

Another interpretation

I originally tried to find a linear progression here but I couldn't because I was trying to find one that connects the entire passage.

If we only look at measure 5 beat 3 until measure 6 beat 3, it is a linear progression connecting `iv42` and `vii°42/V/V`.

I also found https://www.harmony.org.uk/book/linear_progressions.htm, which has a Mozart example with a similarly unresolved V chord in the progression.

Some people believe that Beethoven was inspired by this Mozart sonata. I think that makes sense. There are many similarities between the two and Beethoven just takes it to the next level.

• I learned the concept of linear progression back in school, but I'm not sure that I can find the two functional chords that it's connecting. And it still doesn't explain that unresolved major-minor 7th chord. I guess nobody made the rule that it has to be resolved, but I find it really interesting. Commented Nov 26, 2021 at 14:27
• @Aaron. Oh. My bad. I meant Eb. I'll edit the post Commented Nov 26, 2021 at 16:26

### TL;DR

Beethoven is using a combination of common-tone and enharmonic modulation. Common-tone diminished chords are discussed in various posts here; a list can be found here. Enharmonic modulation, as used in mm. 5–8, is where a diminished chord is reinterpreted according to an enharmonically equivalent diminished chord.

### Analysis

measure 5

Begins in `III` (E♭), moving to `ii[4-2]/III` (Fm7/Eb) on beat 3.

The chord on beat 4 is spelled as `viio[6-5]` (Bdim/D), but interpretively, it's rooted on F: a common-tone chord, which undergoes a voice exchange by passing through an apparent `ii[6-4]/III`, but which is best considered as "just a passing chord".

The Bdim spelling is to help clarify the descending motion of the bass: Eb-D-C-B-Bb across m. 5 into m. 6.

• Functionally, the second half of measure 5 is `ii/III`, the harmony being prolonged via a common-tone diminished chord and voice exchange within that chord.
• Contrapuntally, the diminished chord serves to bridge the `ii[4-2]/III` chord with the upcoming `V7/III` chord in m. 6 beat 2.

measure 6

The common-tone diminished chord proved to be a contrapuntal, passing chord connecting measure 5's `ii/III` with `V/III` on beat 2.

Beat 3 immediately employs another common-tone diminished chord, this time Bbdim, but spelled as C#dim (`viio[4-2]/V/V`) to hint at the arrival on D major (`V/V`) in m. 7.

Beats 3 and 4 comprise a contrapuntal expansion of the diminished chord, again via voice exchange, which conveniently places the "passing" `V/V/V` (A major) on beat 4 — a strong rhythmic position compared to the diminished chord on the &-of-3 and &-of-4.

measures 7 and 8

After an initial arrival on `V/V` (D major), beat 3 sees the arrival of another common-tone diminished chord: Ddim spelled as Bdim to reflect the larger context of C minor.

This time, instead of voice exchange, Beethoven takes the diminished chord through its various inversions, all of which serve as an extended chromatic passing chord between `V/V` in measure 7 with `V7` in measure 8.

Finally, `V7` is expanded by briefly visiting `iv6` (Fmin/Ab) on beat 4.

• Thanks for the detailed analysis! Based on what I've learned, the root of the resolution of a CT-dimished chord must appear in the CT chord. But this never happens in the score. However, I think your interpretation of the enharmonic spelling makes sense (though I'm not really sure what the problem is to change B natural to C-flat at the end of mm. 5 and the beginning of mm. 6). Commented Nov 27, 2021 at 10:11
• (Don't know how to put new lines in a comment. Let me edit my post instead) So mm. 5 beat 4 and mm. 6 beat 1-2 are simply [vii -> V] of Eb major (III). Then this V is never resolved and moves to [vii -> V] of D (V/V) in mm. 6 beat 3-4 and mm. 7 beat 1-2. Everything after until mm. 9 is [vii -> V -> iv -> V] of c minor. If we treat those [vii -> V]'s as voice leading additions, the entire passage is basically [III -> iv -> V/III (or VII, unresolved) -> V/V -> V -> iv -> V -> i] of c minor. The unresolved V is still very interesting. Commented Nov 27, 2021 at 10:14
• @lbbl59 - I'll note that your "V -> iv" is actually V -> iv6, which, according to my Royal Conservatory of Music-approved textbook, actually is a permitted chord progression in common practice period harmony due to its strong resemblance to a V -> VI deceptive cadence. Commented Nov 27, 2021 at 14:33
• @Dekkadeci, I ignored the inversions and showed only the functions. I thought that sounds smooth because of the voice leading but I think the textbook is right that it sounds like V->VI. Similar to how an N chord sounds like IV. Commented Nov 27, 2021 at 21:56