Sonata Form: A Brief Introduction
Sonata form is a method of organizing musical ideas in instrumental music. It’s one of the most pervasive musical forms in classical music and the defining form of the Classical period (c. 1750–c. 1825). Sonata form appears in the first movements of not only piano sonatas, sonatas for a solo instrument, and sonatas for a solo instrument and piano, but also piano trios, string trios, piano quartets, string quartets, piano quintets, string quintets, and symphonies—among other genres.
The composer most frequently credited with the invention of sonata form is also the composer who pioneered most of the aforementioned genres: Joseph Haydn (1732–1809). However, Haydn stood on the shoulders of giants, and his notion of sonata form owes much to the works of the Italian composers Domenico Scarlatti (1685–1757) and Giovanni Battista Sammartini (c. 1700–1775). Although Haydn crafted from their mold his own interpretation of sonata form—the one that most people today would recognize as such—Scarlatti and Sammartini laid the philosophical groundwork of conflict and resolution that characterizes all sonata forms.
At its core, sonata form is about the tension between ideas, the transformation of ideas, and their eventual resolution. In sonata form, these are sections known respectively as exposition, development, and recapitulation. This sequence of events mirrors the three “acts” of the hero’s journey in literature: departure (call to adventure), initiation (trials and tribulations), and return (self-explanatory). In fact, musically speaking, sonata form follows a very similar narrative: the exposition section presents musical themes; the development section manipulates those themes, and/or presents new ones; and the recapitulation brings back thematic material from the exposition.
But sonata form is also fluid and has an infinite number of varieties. This is why sonata form in one of Ludwig van Beethoven’s early piano trios sounds quite different from sonata form in one of his late string quartets. (This is also why the noted pianist and writer Charles Rosen called his seminal text on this concept Sonata Forms—not the singular Sonata Form.) Much like the hero’s journey, sonata form is a generalization of specific actions within the plot, or specific procedures within the music. How a composer chooses to present, manipulate, and transform the themes—to break them down, to pull new ones together, to create a climax and set the stage for catharsis—is where the art of sonata form lies.
Exposition
The exposition opens the movement and introduces its defining themes. Fugues—a popular compositional form of the Baroque era (c. 1600–c. 1750)—also have expositions in which the defining themes are introduced, but usually there is only one theme. That theme (or subject) is then repeated, starting on different pitches, and the accompanying notes support that theme. However, in the Classical sonata form, even within the exposition, conflict is present.
The first themes of the exposition are called the first group, and the next themes are called the second group. The word “group” denotes one or more themes in the same key that follow one another. The first group is in the home key of the piece. Therefore, if the key of a sonata is C major, the primary theme will also be in the key of C major. Harmonies at the end of the first group prepare the listener for the second group, which is in a different key, like G major. The fact that the first and second groups have different keys creates a conflict: if the first group is in C major and the second is in G major, the F-natural of C major and the F-sharp of G major create dissonance because, in any given key, each note has to be either natural, sharp, or flat—it can’t be more than one.
The exposition may open with an introduction. Often there is a marked contrast between a slow tempo and grand character in the introduction and a fast tempo and less serious character when the main, thematic material takes over, creating yet another layer of tension within the form. This sequence may be reflected in the title of the movement as, for instance, “Adagio – Allegro” (meaning “slow – fast”). Sometimes the introduction presents material that will be explored later in the piece, as in Wolfgang Amadeus Mozart’s “Dissonance” String Quartet, K. 465. Sometimes the introduction appears throughout the movement and takes on a life of its own, as in Beethoven’s Pathétique Piano Sonata (No. 8, Op. 13) or his String Quartet in A minor (No. 15, Op. 132). Whatever the case, the purpose of the introduction is to create an atmosphere and set the stage for the music that is to come.
Mozart: Quartet in C major for Strings, K. 465 ("Dissonance")
After the music of both the first and second groups has been presented—and repeated, in some cases—the exposition ends in the key of the second group.
These conflicting themes and keys create the illusion of two separate planes, of two individual kinds of music. Music of the Baroque period unfolds as an organic, almost evolutionary process. In the Classical era, the perception of conflict between multiple ideas took precedence. Music of the Baroque period placed great emphasis upon the notion of continuity: the key of the music might change frequently over time, and the melodies may seem to flow with no boundaries. In the Classical era, music was more rigidly structured: short stretches of music make up phrases, and these in turn can combine (often symmetrically) to shape sentences and periods. To terminate these phrases, sentences, and periods are brief harmonic progressions called cadences, as well as dramatic pauses or changes in dynamics or rhythm, or some combination of these.
Terms for these musical features were not around in the late 18th century (when they became more common), but a tendency towards segmented lengths of music, deliberate juxtapositions of keys, and more defined melodies was gradually becoming the new vogue. New parameters of music were becoming more clearly defined.
Development
The development section falls in the middle of the movement. Its character can range from long and complicated to short and sweet. There are many ways composers have structured this section, but ultimately its function within the movement is to create instability, while also preparing for a return to the home key (retransition). Although there is also some degree of instability in the exposition because the theme groups conflict with one another, they stand on stable ground: the harmonies emphasize their key and change at a slower pace. In the development, the harmonies transform more rapidly, and the themes are often broken up—although some sonatas introduce new themes in the development.
What allows the themes to be broken up is one of the defining concepts of sonata form: the motive. (The terms “motive” and “motif” are often used interchangeably, but the latter can imply an extramusical association, and, in this case, the concept is purely musical.) A motive is a short series of notes, and it typically derives from the main theme. Sometimes the theme comprises only a combination of motives, and sometimes a motive is simply one small part of the theme. One of the most famous motives comes from Beethoven’s Fifth Symphony: the opening four notes (duh-duh-duh-DUUUH) are actually a motive. The repetition of this motive, starting on different pitches, makes up the theme.
It’s important to note that a motive is not just about pitch: it’s also (and often primarily) about rhythm. Music is a substance of many dimensions, and both pitch and rhythm are, on their own, a dimension of relatively equal significance. This is why you can tap out the rhythm of the opening theme from Beethoven’s Fifth and people will immediately know what you’re referencing. If a motive is made up of only the rhythmic dimension, it’s called a rhythmic motive. Focusing on only the rhythmic component of a motive allows a composer more freedom in choosing pitches to develop their ideas.
Motives are not unique to sonata form. Composers since at least the 15th century had been using motives to develop their ideas. But how the motives were used within sonata form was unique to the genre: they now operated as tools to elucidate the form—markers to signify important junctures in the structure.
Carl Philipp Emanuel Bach (Johann Sebastian Bach’s son) played an important role in this rethinking of the motive. In the early 18th century, his father had used motives to create thematic cohesion; C.P.E. used them to differentiate between ideas and sections of the movement. However, the younger Bach was relatively limited in his conception of the motive, which, in his music, was assigned to either the melody or the accompaniment, but not both.
In 1781, Haydn, who had already gained notoriety as a composer of string quartets, wrote a new collection of string quartets (Op. 33) in what he called “a new and special manner.” Although these works made quite a few new strides in the genre of the string quartet, the sharing of motives between the melody and accompaniment was one of their greatest contributions. This was a device Haydn had employed previously, but in the Op. 33 quartets, he takes it to a whole new level.
Haydn: Quartet in G major for Strings, Op. 33 No. 5
Motives appear in the exposition to delineate the themes and provide motivic unity, but in the development, they steer much of the action. Full themes often do appear in the development, but the shortness of motives allows them to fit into the frequently changing harmonies that characterize the development section. Motives therefore allow for a partial identity of the theme to exist throughout the section; they operate as a familiar vehicle over uncertain terrain.
The development often ends dramatically, with stable, strongly emphasized harmonies precipitating the arrival of the final section: the recapitulation.
Recapitulation
The recapitulation returns to themes from the exposition, and its primary purpose in the form is to reestablish stability. However, it’s not simply a repeat of the exposition. In fact, the order of the themes is often not the same as it was in the exposition.
A return to the first group opens the recapitulation. But where a composer starts in the first group is not necessarily at the beginning. In fact, by the mid-18th century, it was common practice to start a bit into the first group before returning to the opening theme later on in the recapitulation. By the late 18th century, it was more common to begin the recapitulation with the opening theme of the exposition. And thus the (inaccurate) stereotype of the recapitulation as merely a restatement of the exposition.
A more accurate way to describe the recapitulation is as a reconceptualization of the exposition. The exposition took us away from stability and towards the action of the plot. The recapitulation takes us from instability and towards a final resolution of the drama.
For this reason, the most important part of the recapitulation is actually the return to the second group. In the exposition, the key of the second group was different from the home key of the piece; this disparity established the overarching dissonance of the movement and initiated the journey towards increasing instability. The appearance of the second group in the home key of the piece signals an arrival point—a resolution of dissonance on a broad scale.
The length and structure of the recapitulation is largely dependent upon the development. Sonata form is all about proportions, and if there is a particularly high amount of tension in the development, the recapitulation must work even harder to solidify the perception of stability. Therefore, development may still occur in the recapitulation. It’s relatively common to find in the recapitulation a second development that transitions the thematic material to new keys and makes the final return to the home key all the more emphatic.
The length of the recapitulation may also be augmented by the presence of a coda. The coda is a section at the end of the movement that presents content differing from the material immediately preceding it. Its function within the form is to provide a satisfying sense of closure which the movement otherwise wouldn’t have had. Often the coda is simply a short restatement of the main thematic material to round off end of the movement. And sometimes—as is frequently the case with Beethoven—the coda is very long and contains some of the most dramatic music in the entire movement.
Sonata Form Beyond the Classical Era
It may surprise many to learn that the term “sonata” was not associated with a type of movement form until the 1830s, after the main composers associated with the form had passed away. And it wasn’t until the late 1830s or early 1840s that the term “sonata form” was clearly defined. For the Classical-era composers, sonata form was a certain set of procedures which they intuitively understood from mentorship and studying the music of their predecessors; certain aspects of sonata form they simply invented themselves.
This fresh understanding of sonata form impelled composers in the 19th century both to approach sonata form with a newfound awareness of its meaning and to experiment with what it could mean.
Exact repetitions of sections (as had been common in the Classical era) began to disappear. Sometimes new themes would develop from previous themes. The coda took precedence over the recapitulation, which, in some cases, was skipped over entirely.
Paralleling the 19th-century focus on harmonic exploration was a rethinking of harmonic relationships between keys in sonata form. In the Classical era, movement between keys was relatively defined: if the first group is in this key, then the second group must be in that key; if the exposition starts in this key, then the development must begin in that key.
The Romantics (c. 1825–c. 1900) pushed the boundaries of these relationships. Even in the early 19th century, composers like Beethoven and Franz Schubert challenged the commonly held notions of what key changes were possible within sonata form. One notable example is Schubert’s 1828 String Quintet in C major, D. 956 (also called the “Cello Quintet" because of the addition of a cello to a string quartet). In this performance of the Cello Quintet at the Chamber Music Society of Lincoln Center, notice how, about a minute and three quarters in, the second theme sounds almost as if it’s in the wrong key. That’s because the G-major chord ending the first group typically would resolve to the home key of the piece—C major. However, the second theme is in the distantly related key of E-flat major, which has three more flats than C major. Such a move falls outside the conventional key relationships of sonata form.
Schubert: Quintet in C major for Two Violins, Viola, and Two Cellos, D. 956
In the 20th century, the modernist evolution of tonality changed the expectation of key relationships in sonata form. In some works, these relationships are completely preserved; in some, they’re hinted at but not clearly articulated; and in some, all sense of key is lost.
The first movement of Hungarian composer Béla Bartók’s Fourth String Quartet, written in 1928 (100 years after Schubert’s Cello Quintet), occupies a middle territory. Tonality is not completely lost, but it’s difficult to pin down harmonies in each of its sections. Nevertheless, one can clearly hear a sonata form in this performance at the Chamber Music Society of Lincoln Center: a first theme group at the very beginning, a second theme group 30 seconds in, a development section at 1:47, a recapitulation at 3:20, and a coda at 4:38. What brings out these sections are changes in melody, pitch content, dynamics, rhythm, or instrumentation; harmony occupies a place of lower priority.
Bartók: Quartet No. 4 for Strings
Nearly 100 years after Bartók’s quartet, sonata form continues to be a dominant method of composition. Certain movements within classical music have threatened its existence: in the latter half of the 19th century, the War of the Romantics caused some composers to throw out the genres of the Classical era like the string quartet and the symphony; in the 1950s, radical experiments in compositional thinking snarled at the classical strictures of the past; in the 1960s and ‘70s, minimalist composers reduced music down to drones, pulses, and out-of-phase recordings, drawing focus away from the music as object and towards the listener as subject.
But during every one of those periods, sonata form still existed. And, inevitably, as one generation pushed away from that most recognizable of classical forms, there was a gravitational pull bringing classical music back to its core. This inexplicable force permeates so much of the classical repertoire. Even when the elements of sonata form—exposition, development, recapitulation—are absent, the principles—tension, transformation, resolution—still remain. They’ve become defining components of classical composition, part of the unbreakable DNA of classical music.
____________
Article by Jesse Jennings