Mozarts Sonata No. 5 is part of the earliest group of sonatas that Mozart published during the mid 1770. This particular sonata was composed in Munich during his stay to compose La Finta Giardiniera. This sonata reflects a pivotal period in Mozart’s career as he was still refining his musical voice whilst seeking greater greater recognition in Europe’s music scene. The first movement, Allegro exemplifies an early classical sonata form through its clear layout of exposition, brief development, and recapitulation. With its elegant, yet economical melodic and thematic construction and concise harmonic design, the Allegro of K. 283 embodies the classical ideal of the piano sonata. 

The sonata form is one of, if not the most prevalent forms in the Classical period. Offering composers freedom to explore, harmonically and otherwise, the themes they set out in the exposition. A sonata goes as follows: Exposition, where the composers introduces two contrasting subjects( or themes) — the first in the tonic key and the second in the dominant key. This is followed by a development, in which the themes are explored, often in unexpected keys, leading to harmonic tension. The form concludes with the recapitulation, in which the subjects are reintroduced in the tonic key, tensions resolved and concluding the piece neatly. Composers may chose to add short intros or codas,  but these don’t affect the overall structure of this form.

At first, this form may resemble a ternary structure,A (exposition), B (development) and A (recapitulation). However, the Sonata is most closely related to a rounded binary form. This is because Binary form emphasizes not only on the relationship of themes but also tonalities. Bernard Jacobson, artistic director or North Netherlands orchestra and author of The Music of Johannes Brahms puts it like this: “In binary form the structure depends on the interrelationship not only of themes but also of tonalities, or keys, the particular sets of notes and chords used in each part. Thus, the initial part, which is repeated, leads directly into the second part by ending in the new key in which the second part begins. The second, also repeated, moves from the new key back to the original key, in which it ends. The second part thus completes the first.”

The exposition begins with him setting out his first subject. The anacrusis, followed by the ensuing bar, outline the chord of G Major, firmly establishing his place in the tonic key. This is further emphasized by an arpeggiated G Major chord in the left hand. His sole use of chord tones further reinforces his place in G Major and creates a solid harmonic base from which to develop from. His first theme is playful and cheerful, with symmetrical phrases, lasting equal length. The first line relies almost entirely on the tonic and dominant chords, and although there is a perfect cadence, Mozart quickly moves past it to introduce a new melodic idea. His contrast of scalar motion and chordal motion creates a noticeable textural change, This serves to set up the first perfect authentic cadence.  Following this we see a slight development of his opening theme. He uses the same chord progression but changes the melody slightly by putting it in a deeper, more serious register. 

Once his first subject has been laid out, he then needs to transition to another key for his second subject. We anticipate that he will modulate to the dominant key, D Major, for his second subject. He does exactly this. The modulation is achieved through his use of sequences and by adding a C#. In this he has seamlessly transitioned to the key of D Major. 

Mozart now creates his second subject in D Major, which shares some characteristics with his first theme, such as his use of only the tonic and dominant chords when setting out this subject. His accompaniment changes, this is to contrast the accompaniment of the first subject. In his initial bars the melody is quite restrained, yet quickly intensifies in complexity by becoming more chordal and faster. He uses sequences extensively throughout the beginning of the second subject which then begins to use more chromaticism in both the melody and the accompaniment. His second subject is both longer and has less predictable phrase lengths than the first subject which creates an interesting contrast. After his second subject he has a small codetta in D Major, as we expect

The development is now beginning. Noticeably he has a completely new theme to begin his development. His development is short at around 10 bars. It is not evident that Mozart changes keys throughout this short development. He continues, it seems, in D major with his addition of C#. For a brief moment we could be led to think he modulates to the key of A major with his addition of a G#. However, this is more on an ornamental trill than a true modulation. 

  The transition back to recapitulation is very interesting. He first sets it up by giving us a dominate pedal for a number of bars. This is a common way for classical composers to signal that a change is about to happen. He then uses a sequence to fully transition us back to G major. The first part of the sequence outlines a D Major chord. Then the next half of the sequence outlines a F# diminished chord which is the VII chord of G Major. This transitions back to G Major for the recapitulation. 

The recapitulation begins with an exact repeat of his first subject back in G Major. His accompaniment slightly changes but is still very in keeping with the original feel of the first subject. In his accompaniment he gives us a slight tease in A-Minor through his addition of a G#. Then comes the transition that will not modulate. He achieves this by very briefly modulating to D Major by adding a C#. But he does not continue in D Major and just gives us a perfect cadence back in G major. His second subject, which is now in G Major is an exact repeat of the original second subject. He has a coda in G Major and the piece ends gracefully.

Mozart's Sonata in G major, K. 283, exemplifies the classical ideals of clarity, balance, and harmonic structure through its seamless use of sonata form. The interplay between the tonic and dominant keys, along with clever modulations and textural contrasts, illustrates Mozart's early mastery of thematic development within a structured form. While the development section is notably brief—almost compressed compared to the exposition and recapitulation—it still serves its purpose, providing just enough harmonic and thematic tension before resolving back to the tonic. This conciseness reflects the economy and elegance that define the movement as a whole. The Allegro is both playful and poised, demonstrating Mozart’s ability to craft refined melodic material while adhering to classical principles. As one of his earliest published sonatas, it offers insight into his emerging style and stands as a testament to his growing compositional confidence during a formative period in his career.

Bibliography

https://www.earlymusicworld.com/mozart-s-salzburg

https://allaboutmozart.com/mozart-1774/

https://www.britannica.com/art/sonata-form

https://www.britannica.com/biography/Wolfgang-Amadeus-Mozart

https://www.operaphila.org/whats-on/on-stage-2016-2017/figaro/composer/

https://viva.pressbooks.pub/openmusictheory/chapter/sonata-form/

https://music.arts.uci.edu/abauer/4.1/readings/Laitz_Complete_Musician_Oxford_27_Sonata_Form.pdf

https://tonic-chord.com/mozart-piano-sonata-no-5-in-g-major-k-283-analysis/

Thank you also to Dr. Jamie Liddle, for  being a valuable asset to bounce ideas off.