Wolfgang Amadeus Mozart, 1756-1791
String Quartet in d minor, K. 421, 2nd of the "Haydn" Quartets, 1783
In the summer of 1783, Mozart completed his second string quartet in the series of six that he ultimately dedicated to Haydn. They were Mozart's greatest in the genre, arguably the greatest quartets by any composer up to that time. The set is noteworthy for its breadth and diversity of technical means and expressive effects. Each quartet is unique and distinct in form and character. The second Quartet, K. 421 in d minor, owes its individuality to its tonality: it is the only one in a minor key. Composers of the era typically published a set of quartets as a single opus, commonly featuring at least one in a minor key. As the primary key of a quartet, minor keys were used sparingly lest their severity overwhelm. As a showcase of this multi-faceted severity, K. 421 is especially potent, among the most intense of Mozart's works, perhaps the most intense quartet in general before Beethoven.
The interplay of contrasting keys was a crucial dramatic aspect of classical music. Based on the sonata principle, a set of keys structured the development of music within a movement and across the set of movements in a quartet. This drama is especially vivid in a minor key as the chief contrast is minor versus major, a difference as readily discernable as typical adjective pairs suggest: dark and light or sad and happy. A work is said to be "written in a key" when that key predominates. In the case of a minor key, the word "gravity" is particularly apt. Despite episodes in a major key, the minor key triumphs, pulling light into dark, hope into despair. In doing so, even the brightest musical interludes labor in shadow. As a special occasion, such a work is particularly compelling, delectable in its devastation.
Three of this quartet's four movements are saturated by its ruling minor key. All three movements drive their dark modality to extreme points of tension and definitive victory. The first movement pits minor against major as first and second themes. From volatile development to a recapitulation of despair, the minor subdues its foe, twisting its theme from major to minor as the fate of sonata dictates. The third movement is a Menuetto from Hades, harsh and tragic as it engulfs the delicate Trio within. The final movement theme and variations deliver ultimate dramatic peaks: a violent variation slashed with syncopation, and a relentless reprise fractured into icy shards. Despite its respite in a major key, even the second movement blanches with an interlude of gloom. Yet contrast is essential to the narrative. The precious moments of brightness bloom like rare flowers: the lyrical second movement, the brief, sparkling trio, and the ambrosia of the finale's fourth variation.