Non-human mammals play a wide variety of roles in human culture. They are the most popular of pets, with tens of millions of dogs, cats and other animals including rabbits and mice kept by families around the world. Mammals such as mammoths, horses and deer are among the earliest subjects of art, being found in Upper Paleolithic cave paintings such as at Lascaux. Major artists such as Albrecht Drer, George Stubbs and Edwin Landseer are known for their portraits of mammals. Many species of mammals have been hunted for sport and for food; deer and wild boar are especially popular as game animals. Mammals such as horses and dogs are widely raced for sport, often combined with betting on the outcome. There is a tension between the role of animals as companions to humans, and their existence as individuals with rights of their own. Mammals further play a wide variety of roles in literature, film, mythology, and religion.
Music theory encompasses the nature and mechanics of music. It often involves identifying patterns that govern composers' techniques and examining the language and notation of music. In a grand sense, music theory distills and analyzes the parameters or elements of music rhythm, harmony (harmonic function), melody, structure, form, and texture. Broadly, music theory may include any statement, belief, or conception of or about music. People who study these properties are known as music theorists. Some have applied acoustics, human physiology, and psychology to the explanation of how and why music is perceived.
Expressive qualities are those elements in music that create change in music without changing the main pitches or substantially changing the rhythms of the melody and its accompaniment. Performers, including singers and instrumentalists, can add musical expression to a song or piece by adding phrasing, by adding effects such as vibrato (with voice and some instruments, such as guitar, violin, brass instruments and woodwinds), dynamics (the loudness or softness of piece or a section of it), tempo fluctuations (e.g., ritardando or accelerando, which are, respectively slowing down and speeding up the tempo), by adding pauses or fermatas on a cadence, and by changing the articulation of the notes (e.g., making notes more pronounced or accented, by making notes more legato, which means smoothly connected, or by making notes shorter).
Romantic music (c. 1810 to 1900) from the 19th century had many elements in common with the Romantic styles in literature and painting of the era. Romanticism was an artistic, literary, and intellectual movement was characterized by its emphasis on emotion and individualism as well as glorification of all the past and nature. Romantic music expanded beyond the rigid styles and forms of the Classical era into more passionate, dramatic expressive pieces and songs. Romantic composers such as Wagner and Brahms attempted to increase emotional expression and power in their music to describe deeper truths or human feelings. With symphonic tone poems, composers tried to tell stories and evoke images or landscapes using instrumental music. Some composers promoted nationalistic pride with patriotic orchestral music inspired by folk music. The emotional and expressive qualities of music came to take precedence over tradition.
Romantic composers grew in idiosyncrasy, and went further in the syncretism of exploring different art-forms in a musical context, (such as literature), history (historical figures and legends), or nature itself. Romantic love or longing was a prevalent theme in many works composed during this period. In some cases the formal structures from the classical period continued to be used (e.g., the sonata form used in string quartets and symphonies), but these forms were expanded and altered. In many cases, new approaches were explored for existing genres, forms, and functions. Also, new forms were created that were deemed better suited to the new subject matter. Composers continued to develop opera and ballet music, exploring new styles and themes.
In the years after 1800, the music developed by Ludwig van Beethoven and Franz Schubert introduced a more dramatic, expressive style. In Beethoven's case, short motifs, developed organically, came to replace melody as the most significant compositional unit (an example is the distinctive four note figure used in his Fifth Symphony). Later Romantic composers such as Pyotr Ilyich Tchaikovsky, Antonn Dvok, and Gustav Mahler used more unusual chords and more dissonance to create dramatic tension. They generated complex and often much longer musical works. During the late Romantic period, composers explored dramatic chromatic alterations of tonality, such as extended chords and altered chords, which created new sound "colours". The late 19th century saw a dramatic expansion in the size of the orchestra, and the industrial revolution helped to create better instruments, creating a more powerful sound. Public concerts became an important part of well-to-do urban society. It also saw a new diversity in theatre music, including operetta, and musical comedy and other forms of musical theatre.