Mozart’s Allegro in G minor K312/590d: A Partial Sonata Composition Explained

It is a mystery that often intrigues music scholars: why did Wolfgang Amadeus Mozart abandon his Allegro in G minor, K312/590d, a piece that was only partly completed and left unfinished? This article explores the history and potential reasons behind this incomplete composition and provides insights into how this unique piece fits into Mozart's larger musical body of work.

Unveiling the Incorrect Attribution

The confusion regarding the composition of K312/590d began with Ludwig von K?chel's Inventarium catalog in 1862, where he mistakenly dated it to Salzburg in 1774. However, a more rigorous examination of the manuscript's watermarks revealed the true origin: the piece was composed in Vienna in 1790. This discovery clarifies that K312/590d was penned during what is often considered the late phase of Mozart's musical career in the Austrian capital.

Uncompleted Motifs and Reconstruction Efforts

Mozart indeed did not complete the Sonata – he even abandoned the effort after 106 bars of the first movement. Attempts have been made to reconstruct the missing segments of this Allegro. One of the more convincing reconstructions, in my opinion, is by Robert Levin. His work is a testament to the intricate structures and emotive qualities Mozart aimed to achieve with this incomplete piece.

Mozart’s Context and the Prussian Commission

The year 1789 marked a significant period in Mozart's life. He traveled to the court of Kaiser Frederick William II in Potsdam, where he was commissioned to write a set of three string quartets and a set of piano sonatas for the Kaiser's daughter Friederike. This commission included the composition of the first of the “Prussian” Quartets (K.375) and the first of these so-called “easy” sonatas (K.576).

Despite receiving payment for the two completed commissions, the remaining fees never materialized. This suggests that Mozart began to aerial the idea of further works for this commission, possibly due to a realization that the promised commissions might not be fruitful. Notwithstanding, he did complete the last two “Prussian” Quartets (K.589 and K.590), though they did not receive the same dedication as K.575.

The Cessation of a Potential Sonata

The non-completion of the Allegro in G minor, K312, appears to be a pivotal point in Mozart's musical activity. It is highly likely that the cessation of the composition of this Sonata was directly linked to the drying up of the Prussian commission. The fact that he was more inclined to complete the string quartets K.589 and K.590 indicates his belief in the commercial value of these works, but not the piano sonatas for the Kaiser’s daughter.

Ultimately, the abandonment of the Allegro in G minor K312/590d is a reminder that even master composers are subject to the constraints of patronage and commercial appeal. This unfinished composition, while regrettable, remains a treasured piece, particularly in the key of G minor, and is a testament to the unique musical genius of Mozart.