Paul Hindemith in the context of "Bach"

In music, consonance and dissonance are categorizations of simultaneous or successive sounds. Within the Western tradition, some listeners associate consonance with sweetness, pleasantness, and acceptability, and dissonance with harshness, unpleasantness, or unacceptability, although there is broad acknowledgement that this depends also on familiarity and musical expertise. The terms form a structural dichotomy in which they define each other by mutual exclusion: a consonance is what is not dissonant, and a dissonance is what is not consonant. However, a finer consideration shows that the distinction forms a gradation, from the most consonant to the most dissonant. In casual discourse, as German composer and music theorist Paul Hindemith stressed,

The term sonance has been proposed to encompass or refer indistinctly to the terms consonance and dissonance.

Gebrauchsmusik (German pronunciation: [ɡəˈbʁaʊ̯xsmuˌziːk]) is a German term, meaning "utility music", for music that exists not only for its own sake, but which was composed for some specific, identifiable purpose. This purpose can be a particular historical event, like a political rally or a military ceremony, or it can be more general, as with music written to accompany dance, or music written for amateurs or students to perform.

While composer Paul Hindemith is probably the figure most identified with this expression, it seems to have been coined within the realm of musicology rather than composition. In the late 19th and early 20th centuries, the modern academic discipline of musicology was formulated by a mainly German group of scholars who were interested not only in formal development and biographical data, but also to an extent in the sociopolitical position of music throughout history, and the relationship of music and musicians to society at large.

Chamber opera is a designation for operas written to be performed with a chamber ensemble rather than a full orchestra. Early 20th-century operas of this type include Paul Hindemith's Cardillac (1926). Earlier small-scale operas such as Pergolesi's La serva padrona (1733) are sometimes known as chamber operas.

Other 20th-century examples include Gustav Holst's Savitri (1916). Benjamin Britten wrote works in this category in the 1940s when the English Opera Group needed works that could easily be taken on tour and performed in a variety of small performance spaces. The Rape of Lucretia (1946) was his first example in the genre, and Britten followed it with Albert Herring (1947), The Turn of the Screw (1954) and Curlew River (1964). Other composers, including Hans Werner Henze, Harrison Birtwistle, Thomas Adès, George Benjamin, William Walton, and Philip Glass have written in this genre.