The revolutionary spirit ushered in by the Enlightenment infused Western artists with ideals of liberty and individualism. Musicians grew impatient with the restraints of Classicism and sought their own voice, creating divergent schools of musical thought. Unlike prior eras where composers adhered to an accepted core of beliefs and practices, there is not an exact definition of the Romantic style.
Expressive Content
There is one characteristic central to all Romantic music: evocation of emotion as a primary goal. Expressive content is first and foremost in the Romantic style.
The Romantic era had two main schools of musical thought: Idealists and Realists.
Idealists
Idealists believed that music was complete in itself; that is, stories, poetry, fanciful titles or suggestions of atmosphere were not needed. Their ideas embody the essence of absolute music. Here's a piece written by an Idealist composer:
Ländler in A Minor | Franz Schubert, 1797-1828
Realists
Realists insisted that music could and should communicate extra musical ideas: tell a story, suggest a mood or scene, imitate nature, champion political ideals, etc. Their ideas embody the essence of program music. Realist music usually features a descriptive title, accompanying poem and/or story (program).
Within the realist camp, Nationalism strove to evoke patriotic feeling and cultural pride through use of folklore, folk and popular music, or by creating music suggestive of folk and popular music. Here's a taste of Nationalistic music:
Orientale | César Antonovich Cui, 1835-1918
Romantic Audiences
In the music world, grand spectacle and intimacy opposed one another. Many composers favored vast numbers of performers and brilliant technical display, appealing to the tastes of the middle class with opera, concerto, symphony and ballet. The tastes of aristocrats and the Church were of secondary concern. In contrast, a smaller group of composers embraced intimate forms with delicate textures: solo song, solo piano works, chamber music, etc. These works were written to be played in exclusive salons for highly cultured audiences.
Musical Style
Formal Organization
Unlike prior eras, Romantic era composers studied music history and knew the styles and forms of their predecessors, especially the music of Beethoven, Mozart and Haydn. Thus, romantics continued to compose in Classical forms and genres, but freely modifying them to fit nineteenth century tastes.
The sonata-form remained an important organizational structure within movements. However, Romantic use of the sonata-form was not as clear and precise as was in the Classical era: boundaries between musical sections were often vague and overlapping. Romantic forms were not as balanced and symmetrical as those of the Classical era. For example, Romantic development sections tended to be much longer than Classical counterparts.
One-Movement Forms
One-movement forms for piano—ballad, nocturne and fantasy—appeared. Such forms were often spontaneous in feel, as if improvised. They were still based on the presentation of contrasting melodies but shorter and lacked full-blown development sections. Forms such as preludes and etudes may have only one theme but create contrast through changes in texture, rhythm and harmony.
Harmony of the nineteenth century became increasingly complex, chromatic and dissonant. Modulation to remote keys was common: modulation was often used to create musical tension and tonal ambiguity—disorient the listener—not merely as a means to reach a particular key. In other words, the constantly shifting keys and chromaticism were used to control the emotional content of the music.
Melody
Melody is characterized by an intensity of personal feelings. Exciting climaxes, melodic leaps, chromaticism and frequent changes in dynamics served to create the tension needed for this type of expression. Melody is often fragmentary, filled with rhythmic interruptions and use of irregular phrase lengths.
Mood
Like the prior Classical era, Romantic works frequently fluctuate in mood, often between opposites: turbulence to restfulness, steadfastness to playfulness, happy to sad, etc. However, these fluctuations tended to be more exaggerated and extreme compared to Classical music. Mood changes were achieved via mode and key changes, sudden and drastic dynamic shifts, changes in instrumentation, heavy use of chromaticism (notes and chords outside the key), etc.
Dynamics
Romantic composers continued the Classical practice of using dynamics as an expressive device. Romantic stylistic differences are in the extremes of use: dynamics were used more frequently, with finer gradations and larger ranges than Classical composers. While fortissimo and pianissimo were used sparingly by Haydn and Mozart, improvements in instrument design and enlargement of the orchestra made extreme dynamics practical in the nineteenth century. Indeed, firearms, including cannons, were deployed in many Romantic pieces.
A Concert of Hector Berlioz | Andreas Geiger, 1765-1856 | French press lampoons the dynamic extremes of the Romantic orchestra with huge low brass section, percussion and cannon. | L'Illustration, November 15, 1845
Here's a short example of Romantic era style:
Prelude Op. 28 No. 4 | Frédéric Chopin, 1810-49 | This short piece exhibits extreme dynamics, chromatic harmony and intense emotional expression.
Musical Instruments
The nineteenth century saw numerous improvements to musical instruments: keys on woodwinds, valves on brass, metal frame on piano, larger guitars, etc. Such changes increased the technical potential: larger pitch range and increased volume. Many of these improvements are still standard on modern instruments.
B-Flat Trumpet | The addition of valves on brass instruments to change pitch extended range and improved intonation. | Wikimedia Commons
Orchestra
The orchestras of Haydn and Mozart were small, typically twenty-five pieces. Romantic orchestras were much larger with full brass, woodwind and percussion sections—a full marching band within the orchestra.
Larger orchestras and fuller orchestration techniques meant texture in symphonic music tended to be thicker and opaquer compared to prior eras. The larger orchestra could also produce a wider range of dynamics and timbres. Indeed, timbre became an important aspect of expression: melodies and chords were often created with specific instruments in mind.