Tonality in the context of "Chromatic scale"

In music, form refers to the structure of a musical composition or performance. In his book, Worlds of Music, Jeff Todd Titon suggests that a number of organizational elements may determine the formal structure of a piece of music, such as "the arrangement of musical units of rhythm, melody, and/or harmony that show repetition or variation, the arrangement of the instruments (as in the order of solos in a jazz or bluegrass performance), or the way a symphonic piece is orchestrated", among other factors. It is, "the ways in which a composition is shaped to create a meaningful musical experience for the listener."

These organizational elements may be broken into smaller units called phrases, which express a musical idea but lack sufficient weight to stand alone. Musical form unfolds over time through the expansion and development of these ideas. In tonal harmony, form is articulated primarily through cadences, phrases, and periods. "Form refers to the larger shape of the composition. Form in music is the result of the interaction of the four structural elements," of sound, harmony, melody, and rhythm.

In music, harmony is the concept of combining different sounds in order to create new, distinct musical ideas. Theories of harmony seek to describe or explain the effects created by distinct pitches or tones coinciding with one another; harmonic objects such as chords, textures and tonalities are identified, defined, and categorized in the development of these theories. Harmony is broadly understood to involve both a "vertical" dimension (frequency-space) and a "horizontal" dimension (time-space), and often overlaps with related musical concepts such as melody, timbre, and form.

A particular emphasis on harmony is one of the core concepts underlying the theory and practice of Western music. The study of harmony involves the juxtaposition of individual pitches to create chords, and in turn the juxtaposition of chords to create larger chord progressions. The principles of connection that govern these structures have been the subject of centuries worth of theoretical work and vernacular practice alike.

Atonality in its broadest sense is music that lacks a tonal center, or key. Atonality, in this sense, usually describes compositions written from about the early 20th century to the present day, where a hierarchy of harmonies focusing on a single, central triad is not used, and the notes of the chromatic scale function independently of one another. More narrowly, the term atonality describes music that does not conform to the system of tonal hierarchies that characterized European classical music between the seventeenth and nineteenth centuries. "The repertory of atonal music is characterized by the occurrence of pitches in novel combinations, as well as by the occurrence of familiar pitch combinations in unfamiliar environments".

The term is also occasionally used to describe music that is neither tonal nor serial, especially the pre-twelve-tone music of the Second Viennese School, principally Alban Berg, Arnold Schoenberg, and Anton Webern. However, "as a categorical label, 'atonal' generally means only that the piece is in the Western tradition and is not 'tonal'", although there are longer periods, e.g., medieval, renaissance, and modern modal music to which this definition does not apply. "Serialism arose partly as a means of organizing more coherently the relations used in the pre-serial 'free atonal' music. ... Thus, many useful and crucial insights about even strictly serial music depend only on such basic atonal theory".

Wilhelm Richard Wagner (/ˈvɑːɡnər/ VAHG-nər; German: [ˈvɪlˌhɛlm ˈʁɪçaʁt ˈvaːɡnɐ] ; 22 May 1813 – 13 February 1883) was a German composer, theatre director, essayist, and conductor, best known for his operas—although his mature works are often referred to as music dramas. Unlike most composers, Wagner wrote both the libretti and the music for all of his stage works. He first achieved recognition with works in the Romantic tradition of Carl Maria von Weber and Giacomo Meyerbeer, but revolutionised the genre through his concept of the Gesamtkunstwerk ("total work of art"), which sought to unite poetic, musical, visual, and dramatic elements. In this approach, the drama unfolds as a continuously sung narrative, with the music evolving organically from the text rather than alternating between arias and recitatives. Wagner outlined these ideas in a series of essays published between 1849 and 1852, most fully realising them in the first half of his four-opera cycle Der Ring des Nibelungen (The Ring of the Nibelung).

Wagner's compositions, particularly in his later period, have complex textures, rich harmonies and orchestration, and elaborate leitmotifs—musical phrases associated with individual characters, places, ideas, or plot elements. His advances in musical language, such as extreme chromaticism and quickly shifting tonal centres, greatly influenced the development of classical music; his Tristan und Isolde is regarded as an important precursor to modernist music. Later in life, he softened his ideological stance against traditional operatic forms (e.g., arias, ensembles and choruses), reintroducing them into his last few stage works, including Die Meistersinger von Nürnberg (The Mastersingers of Nuremberg) and Parsifal.

In a musical composition, a chord progression or harmonic progression (informally chord changes, used as a plural, or simply changes) is a succession of chords. Chord progressions are the foundation of harmony in Western musical tradition from the common practice era of classical music to the 21st century. Chord progressions are the foundation of popular music styles (e.g., pop music, rock music), traditional music, as well as genres such as blues and jazz. In these genres, chord progressions are the defining feature on which melody and rhythm are built.

In tonal music, chord progressions have the function of either establishing or otherwise contradicting a tonality, the technical name for what is commonly understood as the "key" of a song or piece. Chord progressions, such as the extremely common chord progression I-V-vi-IV, are usually expressed by Roman numerals in classical music theory. In many styles of popular and traditional music, chord progressions are expressed using the name and "quality" of the chords. For example, the previously mentioned chord progression, in the key of E♭ major, would be written as E♭ major–B♭ major–C minor–A♭ major in a fake book or lead sheet. In the first chord, E♭ major, the "E♭" indicates that the chord is built on the root note "E♭" and the word "major" indicates that a major chord is built on this "E♭" note.

Baroque music (UK: /bəˈrɒk/ or US: /bəˈroʊk/) refers to the period or dominant style of Western classical music composed from about 1600 to 1750. The Baroque style followed the Renaissance period, and was followed in turn by the Classical period after a short transition (the galant style). The Baroque period is divided into three major phases: early, middle, and late. Overlapping in time, they are conventionally dated from 1580 to 1650, from 1630 to 1700, and from 1680 to 1750. Baroque music forms a major portion of the "classical music" canon, and continues to be widely studied, performed, and listened to. The term "baroque" comes from the Portuguese word barroco, meaning "misshapen pearl". Key composers of the Baroque era include Johann Sebastian Bach, George Frideric Handel, Henry Purcell, Antonio Vivaldi, Georg Philipp Telemann, Domenico Scarlatti, Claudio Monteverdi, Girolamo Frescobaldi, Alessandro Scarlatti, Jean-Baptiste Lully, Jean-Philippe Rameau, Arcangelo Corelli, François Couperin, Heinrich Schütz, Dieterich Buxtehude, and Heinrich Ignaz Franz Biber.

The Baroque saw the formalization of common-practice tonality, an approach to writing music in which a song or piece is written in a particular key; this type of harmony has continued to be used extensively in Western classical and popular music. During the Baroque era, professional musicians were expected to be accomplished improvisers of both solo melodic lines and accompaniment parts. Baroque concerts were typically accompanied by a basso continuo group (comprising chord-playing instrumentalists such as harpsichordists and lute players improvising chords from a figured bass part) while a group of bass instruments—viol, cello, double bass—played the bassline. A characteristic Baroque form was the dance suite. While the pieces in a dance suite were inspired by actual dance music, dance suites were designed purely for listening, not for accompanying dancers.

Arnold Schoenberg or Schönberg (13 September 1874 – 13 July 1951) was an Austrian and American composer, music theorist, teacher and writer. He was among the first modernists who transformed the practice of harmony in 20th-century classical music, and a central element of his music was its use of motives as a means of coherence. He propounded concepts like developing variation, the emancipation of the dissonance, and the "unity of musical space".

Schoenberg's early works, like Verklärte Nacht (1899), represented a Brahmsian–Wagnerian synthesis on which he built. Mentoring Anton Webern and Alban Berg, he became the central figure of the Second Viennese School. They consorted with visual artists, published in Der Blaue Reiter, and wrote atonal, expressionist music, attracting fame and stirring debate. In his String Quartet No. 2 (1907–1908), Erwartung (1909), and Pierrot lunaire (1912), Schoenberg visited extremes of emotion; in self-portraits he emphasized his intense gaze. While working on Die Jakobsleiter (from 1914) and Moses und Aron (from 1923), Schoenberg confronted popular antisemitism by returning to Judaism and substantially developed his twelve-tone technique. He systematically interrelated all notes of the chromatic scale in his twelve-tone music, often exploiting combinatorial hexachords and sometimes admitting tonal elements.