5. On the Middle-Period Sonatas
As aforementioned in Part 1, the middle-period would see various forms of experimentation by Beethoven: changes in forms of the structure, exploring keys rarely used by Haydn and Mozart, an increase in the emotional capacity (and hence expressiveness) and creating new textures.

One excellent example would be the Sonata in D major Opus 28 also known as the “Pastorale” Sonata. The 1st movement presents a beautiful singing theme accompanied by a Basso Ostinato (repetition of the bass note). The 2nd theme of the 1st movement is presented with the same accompaniment as the 2nd movement of the “Pathetique” Sonata (Addition of an inner voicing) - Again, signs of a transition to a new style of music.

5.2 Opus 27 No. 2 Sonata Quasi Una Fantasia in C sharp minor “Moonlight”
Arguably one of the most well-loved piano pieces in piano literature, known for the air of mystery and tragedy of the 1st movement and the virtuosity of the 3rd movement. As is similar to the Funeral March sonata, we see a deviation from the traditional form of the sonata. This is evident from the title given by Beethoven, ‘sonata in the manner of a fantasy’ which is more applicable to the famous opening movement Adagio Sostenuto.

And it is the same movement which the poet Ludwig Rellstab likened it to moonlight shining down upon Lake Lucrene, and hence the name “Moonlight” sonata. Here, we see elements of a fantasy: the music sounds almost improvised especially the series of modulations before the repeat of the main theme. The 3rd movement shows yet again, the familiar fiery spirit of Beethoven (through the use of broken chords) previously seen in the 1st movement of the Pathetique.

It is theorized that Chopin’s Fantasie-Impromptu was inspired by this movement, with both pieces sharing the same key (C sharp minor) and even quotations from the music. 

5.4 Opus 57 Sonata in F minor “Appasionata”
Personally, this is my favorite sonata out of the entire cycle and its 3rd movement is especially dear to me. Most would agree that this sonata is the 2nd most difficult sonata Beethoven ever wrote (the most challenging being the Hammerklavier) due to its high technical demands: awkward hand positions and fingering (the 3rd movement being infamous amongst pianists). On top of that, the nuances of the shape of the main motifs, coupled with the large capacity of expression; only the best can manage such a work.

It is here again where one hears the ferocity present in the Pathetique and Moonlight. There is a story told by Beethoven’s secretary Ferdinand Ries which describes the composition of the finale of the sonata: While taking a walk with Beethoven, he hummed the entire way, or sometimes even howled to himself- up and down, up and down, without singing any definitive notes. When Ries asked him what this was, he replied: “A theme for the last Allegro of the sonata has just occurred to me”. When they got back, Beethoven rushed to the piano without taking off his hat and stormed for at least an hour with the new finale.

If there is one word to describe the point of the whole sonata, it would be tension- which erupts in short episodes. The sonata begins with the soft pianissimo, in a low register and coupled with the rhythm of the main theme, the music begs for a volcanic eruption. Indeed, the pianissimo motif is interrupted by forceful chords in the tonic key (F minor).

Then, the 2nd theme gradually enters in its relative major of A flat major, with this air of victory before falling back down in anguish through the use of moto perpetuo (perpetual motion). After many climaxes, the 1st movement ends in exhaustion with the use of a coda similar to the 3rd movement of the Waldstein Sonata (a rapid version of the main theme).

Ending the storm of the 1st movement, the sonata proceeds to with a simple theme and variations in the gentle key of D flat. With the illusion of the loosening of tension, the tranquility is brushed aside and returns to the original mood of fury, signifying the start of the next movement. It opens with a barrage of chords that resemble an outcry. The use of moto perpetuo is evident in this movement to build tension before releasing the rage at the finale (that Beethoven was humming in his walks), ending the movement with desperation and outrage. 

6.1 Opus 106 Sonata in B flat major “Hammerklavier”
A monumental work that speaks of one word- power. This is infamous amongst pianists as not only the most challenging sonata, but also Beethoven’s most challenging piano work. When, it was first published, it was thought to be impossible perform until, Liszt (of course, of all people to do so) broke this myth and performed it one of his concerts, thus elevating his “already-high” status as a virtuoso pianist.

Power- true enough the sonata begins with forceful chords in B flat major that resemble the trumpet sounding. And throughout the whole movement, phrases constructed by chords, backed up by octaves as accompaniment, not only does this signify the high level of technical demand needed, but builds upon the air of victory of the movement.

The 3rd movement contrasts with the 2 movements in terms of speed and emotion. While the first two expresses joy, victory, pride (hence, also suggesting the speed is rather rapid), the 3rd movement, is sorrowful and to directly quote the tempo marking, Adagio Sostenuto. This movement is the longest, with most pianists spending about 16-25 minutes on this movement. But, such a speed is necessary, for it emphasizes the mood of sorrow. Many pianists and critics hold this movement dear to them. Pianist Wilhelm Kempff, known for his interpretations of Beethoven exclaimed that this movement was ‘the most magnificent monologue Beethoven ever wrote’.

The last movement consists of an introduction, followed by a fugue (more evidences of polyphonic incorporation). This movement is the testament of a pianist’s technical skill, for it is far more difficult than that on the fugues of Bach’s Well-Tempered Klavier (but I would say on par with his Art of Fugue). 

6.3 Opus 111 Sonata in C minor
The last sonata he wrote, yet its importance in the cycle is as high as those mentioned above. Beethoven has always associated the key of C minor with that of anguish, rage and tragedy (and thus the stormy qualities of the Pathetique and the 5th Symphony; both of which are in C minor). This sonata is no different in this aspect.

In addition, similar to the Pathetique, it has an introduction before proceeding with the regular sonata-form. But, the focus of this sonata would be the 2nd movement. The 2nd movement consists of a simple theme and variations in the key of C major. Pay particular attention to the 3rd variation (15:56 of the video). Does it resemble any other music genre? Yes, renowned pianist Dame Mitsuko Uchida reckons that it resembles to that of the boogie-woo and hence, proto-jazz or a ragtime. Could it have been possible that Beethoven had introduced the fundamental rhythmic notation (or “swing”) for what is to be the future of music?