Classical music is art music produced or rooted in the traditions of Western culture, including both liturgical (religious) and secular music. While a more precise term is also used to refer to the period from 1750 to 1820 (the Classical period), this article is about the broad span of time from before the 6th century AD to the present day, which includes the Classical period and various other periods.^[1] The central norms of this tradition became codified between 1550 and 1900, which is known as the common-practice period.

European art music is largely distinguished from many other non-European classical and some popular musical forms by its system of staff notation, in use since about the 11th century.^{[2] [3]} Catholic monks developed the first forms of modern European musical notation in order to standardize liturgy throughout the worldwide Church. Western staff notation is used by composers to indicate to the performer the pitches and durations for a piece of music.^[2] In contrast to most popular styles that adopted the song (strophic) form or a derivation of this form, classical music has been noted for its development of highly sophisticated forms of instrumental music such as the symphony, concerto, fugue, sonata, and mixed vocal and instrumental styles such as opera, cantata, and mass.^[4]

The term "classical music" did not appear until the early 19th century, in an attempt to distinctly canonize the period from Johann Sebastian Bach to Ludwig van Beethoven as a golden age.^[5] The earliest reference to "classical music" recorded by the Oxford English Dictionary is from about 1829.^[1][6]

The major time divisions of Western art music are as follows:

Given the wide range of styles in European classical music, from Medieval plainchant sung by monks to Classical and Romantic symphonies for orchestra from the 1700s and 1800s to avant-garde atonal compositions from the 1900s, it is difficult to list characteristics that can be attributed to all works of that type. Nonetheless, a universal characteristic of classical music written since the late 13th century is^[7] the invariable appliance of a standardized system of precise mensural notation (which evolved into modern bar notation after 1600) for all compositions and their accurate performance.^[8] Another is the creation and development of complex pieces of solo instrumental works (e.g., the fugue). The first symphonies were produced during the Classical period, beginning in the mid 18th century, the symphony ensemble and the compositions became prominent features of Classical-period music.^[9]

Works of classical repertoire often exhibit complexity in their use of orchestration, counterpoint, harmony, musical development, rhythm, phrasing, texture, and form. Whereas most popular styles are usually written in song form, classical music is noted for its development of highly sophisticated instrumental musical forms,^[4] like the concerto, symphony and sonata. Classical music is also noted for its use of sophisticated vocal/instrumental forms, such as opera. In opera, vocal soloists and choirs perform staged dramatic works with an orchestra providing accompaniment.

Longer instrumental works are often divided into self-contained pieces, called movements, often with contrasting characters or moods. For instance, symphonies written during the Classical period are usually divided into four movements:

These movements can then be further broken down into a hierarchy of smaller units: first sections, then periods, and finally phrases.

Performers who have studied classical music extensively are said to be "classically trained". This training may come from private lessons from instrument or voice teachers or from completion of a formal program offered by a Conservatory, college or university, such as a Bachelor of Music or Master of Music degree (which includes individual lessons from professors). In classical music, "...extensive formal music education and training, often to postgraduate [Master's degree] level" is required.^[10]

Performance of classical music repertoire requires a proficiency in sight-reading and ensemble playing, harmonic principles, strong ear training (to correct and adjust pitches by ear), knowledge of performance practice (e.g., Baroque ornamentation), and a familiarity with the style/musical idiom expected for a given composer or musical work (e.g., a Brahms symphony or a Mozart concerto).

The key characteristic of European classical music that distinguishes it from popular music and folk music is that the repertoire tends to be written down in musical notation, creating a musical part or score. This score typically determines details of rhythm, pitch, and, where two or more musicians (whether singers or instrumentalists) are involved, how the various parts are coordinated. The written quality of the music has enabled a high level of complexity within them: fugues, for instance, achieve a remarkable marriage of boldly distinctive melodic lines weaving in counterpoint yet creating a coherent harmonic logic.^[11] The use of written notation also preserves a record of the works and enables Classical musicians to perform music from many centuries ago.

Although Classical music in the 2000s has lost most of its tradition for musical improvisation, from the Baroque era to the Romantic era, there are examples of performers who could improvise in the style of their era. In the Baroque era, organ performers would improvise preludes, keyboard performers playing harpsichord would improvise chords from the figured bass symbols beneath the bass notes of the basso continuo part and both vocal and instrumental performers would improvise musical ornaments.^[12] Johann Sebastian Bach was particularly noted for his complex improvisations.^[13] During the Classical era, the composer-performer Mozart was noted for his ability to improvise melodies in different styles.^[14] During the Classical era, some virtuoso soloists would improvise the cadenza sections of a concerto. During the Romantic era, Beethoven would improvise at the piano.^[15] For more information, see Improvisation.

The instruments currently used in most classical music were largely invented before the mid-19th century (often much earlier) and systematized in the 18th and 19th centuries. They consist of the instruments found in an orchestra or in a concert band, together with several other solo instruments (such as the piano, harpsichord, and organ). The symphony orchestra includes members of the string, woodwind, brass, and percussion families of instruments. The concert band consists of members of the woodwind, brass, and percussion families. It generally has a larger variety and number of woodwind and brass instruments than the orchestra but does not have a string section. However, many concert bands use a double bass. The vocal practices changed over the classical period, from the single line monophonic Gregorian chant done by monks in the Medieval period to the complex, polyphonic choral works of the Renaissance and subsequent periods, which used multiple independent vocal melodies at the same time.

The major time divisions of classical music up to 1900 are the Early music period, which includes Medieval (500–1400) and Renaissance (1400–1600) eras, and the Common practice period, which includes the Baroque (1600–1750), Classical (1750–1820) and Romantic (1810–1910) eras. The current period encompasses the 20th century (1901–2000) and includes most of the Early modern musical era (1890–1930), the entire High modern (mid 20th-century), and the first part of the Contemporary (1945 or 1975–current) or Postmodern musical era (1930–current). The 21st century has so far been a continuation of the same period and the same Contemporary/Postmodern musical era which both began mostly in the 20th-century.

The dates are generalizations, since the periods and eras overlap and the categories are somewhat arbitrary, to the point that some authorities reverse terminologies and refer to a common practice "era" comprising baroque, classical, and romantic "periods".^[17] For example, the use of counterpoint and fugue, which is considered characteristic of the Baroque era (or period), was continued by Haydn, who is classified as typical of the Classical era. Beethoven, who is often described as a founder of the Romantic era, and Brahms, who is classified as Romantic, also used counterpoint and fugue, but the romantic and sometimes yearning qualities of their music define their era.

The prefix neo- is used to describe a 19th-, 20th-, or 21st-century composition written in the style of an earlier era, such as Classical or Romantic. Stravinsky's Pulcinella, for example, is a neoclassical composition because it is stylistically similar to works of the Baroque era.

Burgh (2006), suggests that the roots of Western classical music ultimately lie in ancient Egyptian art music via cheironomy and the ancient Egyptian orchestra, which dates to 2695 BC.^[18] The development of individual tones and scales was made by ancient Greeks such as Aristoxenus and Pythagoras.^[19] Pythagoras created a tuning system and helped to codify musical notation. Ancient Greek instruments such as the aulos (a reed instrument) and the lyre (a stringed instrument similar to a small harp) eventually led to several modern-day instruments of a classical orchestra.^[20] The antecedent to the early period was the era of ancient music before the fall of the Roman Empire (476 AD).

The Medieval era includes music from after the fall of Rome to about 1400. Monophonic chant, also called plainsong or Gregorian chant, was the dominant form until about 1100.^[21] Catholic monks developed the first forms of modern European musical notation in order to standardize liturgy throughout the worldwide Church.^[16][22][23] Polyphonic (multi-voiced) music developed from monophonic chant throughout the late Middle Ages and into the Renaissance, including the more complex voicings of motets.

A number of European classical musical instruments have roots in Eastern instruments that were adopted from the medieval Islamic world.^[24] For example, the Arabic rebab is the ancestor of all European bowed string instruments, including the lira, rebec and violin.^[25][26]

Many of the instruments used to perform medieval music still exist, but in different forms. Medieval instruments included the flute, the recorder and plucked string instruments like the lute. As well, early versions of the organ and fiddle (or vielle) existed. Medieval instruments in Europe had most commonly been used singly, often self accompanied with a drone note, or occasionally in parts. From at least as early as the 13th century through the 15th century there was a division of instruments into haut (loud, shrill, outdoor instruments) and bas (quieter, more intimate instruments).^[27] During the earlier medieval period, the vocal music from the liturgical genre, predominantly Gregorian chant, was monophonic, using a single, unaccompanied vocal melody line.^[28] Polyphonic vocal genres, which used multiple independent vocal melodies, began to develop during the high medieval era, becoming prevalent by the later 13th and early 14th century.

Notable Medieval composers include Hildegard of Bingen, Guillaume de Machaut, Léonin, Pérotin, Philippe de Vitry, Francesco Landini, and Johannes Ciconia.

The Renaissance era was from 1400 to 1600. It was characterized by greater use of instrumentation, multiple interweaving melodic lines, and the use of the first bass instruments. Social dancing became more widespread, so musical forms appropriate to accompanying dance began to standardize. It is in this time that the notation of music on a staff and other elements of musical notation began to take shape.^[29] This invention made possible the separation of the composition of a piece of music from its transmission; without written music, transmission was oral, and subject to change every time it was transmitted. With a musical score, a work of music could be performed without the composer's presence.^[21] The invention of the movable-type printing press in the 15th century had far-reaching consequences on the preservation and transmission of music.^[30]

Many instruments originated during the Renaissance; others were variations of, or improvements upon, instruments that had existed previously. Some have survived to the present day; others have disappeared, only to be re-created in order to perform music on period instruments. As in the modern day, instruments may be classified as brass, strings, percussion, and woodwind. Brass instruments in the Renaissance were traditionally played by professionals who were members of Guilds and they included the slide trumpet, the wooden cornet, the valveless trumpet and the sackbut. Stringed instruments included the viol, the rebec, the harp-like lyre, the hurdy-gurdy, the lute, the guitar, the cittern, the bandora, and the orpharion. keyboard instruments with strings included the harpsichord and the clavichord. Percussion instruments include the triangle, the Jew's harp, the tambourine, the bells, the rumble-pot, and various kinds of drums. Woodwind instruments included the double-reed shawm (an early member of the oboe family), the reed pipe, the bagpipe, the transverse flute, the recorder, the dulcian, and the crumhorn. Simple pipe organs existed, but were largely confined to churches, although there were portable varieties.^[31] Printing enabled the standardization of descriptions and specifications of instruments, as well as instruction in their use.^[32]

Vocal music in the Renaissance is noted for the flourishing of an increasingly elaborate polyphonic style. The principal liturgical forms which endured throughout the entire Renaissance period were masses and motets, with some other developments towards the end, especially as composers of sacred music began to adopt secular forms (such as the madrigal) for their own designs. Towards the end of the period, the early dramatic precursors of opera such as monody, the madrigal comedy, and the intermedio are seen. Around 1597, Italian composer Jacopo Peri wrote Dafne, the first work to be called an opera today. He also composed Euridice, the first opera to have survived to the present day.

Notable Renaissance composers include Josquin des Prez, Giovanni Pierluigi da Palestrina, John Dunstaple, Johannes Ockeghem, Orlande de Lassus, Guillaume Du Fay, Gilles Binchois, Thomas Tallis, William Byrd, Giovanni Gabrieli, Carlo Gesualdo, John Dowland, Jacob Obrecht, Adrian Willaert, Jacques Arcadelt, and Cipriano de Rore.

The common practice period is typically defined as the era between the formation and the dissolution of common-practice tonality. The term usually spans roughly two-and-a-half centuries, encompassing the Baroque, Classical, and Romantic periods.

Baroque music is characterized by the use of complex tonal counterpoint and the use of a basso continuo, a continuous bass line. Music became more complex in comparison with the simple songs of all previous periods.^[33] The beginnings of the sonata form took shape in the canzona, as did a more formalized notion of theme and variations. The tonalities of major and minor as means for managing dissonance and chromaticism in music took full shape.^[34]

During the Baroque era, keyboard music played on the harpsichord and pipe organ became increasingly popular, and the violin family of stringed instruments took the form generally seen today. Opera as a staged musical drama began to differentiate itself from earlier musical and dramatic forms, and vocal forms like the cantata and oratorio became more common.^[35] Vocalists for the first time began adding extra notes to the music.^[33]

The theories surrounding equal temperament began to be put in wider practice, especially as it enabled a wider range of chromatic possibilities in hard-to-tune keyboard instruments. Although Bach did not use equal temperament, as a modern piano is generally tuned, changes in the temperaments from the meantone system, common at the time, to various temperaments that made modulation between all keys musically acceptable, made possible Bach's Well-Tempered Clavier.^[36]

Baroque instruments included some instruments from the earlier periods (e.g., the hurdy-gurdy and recorder) and a number of new instruments (e.g, the oboe, bassoon, cello, contrabass and fortepiano). Some instruments from previous eras fell into disuse, such as the shawm, cittern, rackett,and the wooden cornet. The key Baroque instruments for strings included the violin, viol, viola, viola d'amore, cello, contrabass, lute, theorbo (which often played the basso continuo parts), mandolin, Baroque guitar, harp and hurdy-gurdy. Woodwinds included the Baroque flute, Baroque oboe, recorder and the bassoon. Brass instruments included the cornett, natural horn, Baroque trumpet, serpent and the trombone. Keyboard instruments included the clavichord, the tangent piano, the harpsichord, the pipe organ, and, later in the period, the fortepiano (an early version of the piano). Percussion instruments included the timpani, snare drum, tambourine and the castanets.

One major difference between Baroque music and the classical era that followed it is that the types of instruments used in Baroque ensembles were much less standardized. A Baroque ensemble could include one of several different types of keyboard instruments (e.g., pipe organ or harpsichord),^[37] additional stringed chordal instruments (e.g., a lute), bowed strings, woodwinds, and brass instruments, and an unspecified number of bass instruments performing the basso continuo,(e.g., a cello, contrabass, viola, bassoon, serpent, etc.).

Vocal developments in the Baroque era included the development of opera types such as opera seria and opéra comique, and related forms such as oratorios and cantatas.^[38][39]

Important composers of this era include Johann Sebastian Bach, Antonio Vivaldi, George Frideric Handel, Henry Purcell, Claudio Monteverdi, Barbara Strozzi, Domenico Scarlatti, Georg Philipp Telemann, Arcangelo Corelli, Alessandro Scarlatti, Jean-Philippe Rameau, Jean-Baptiste Lully, and Heinrich Schütz.

The term "classical music" has two meanings; the broader meaning includes all Western art music from the Medieval era to the 2000s, and the specific meaning refers to the art music from the 1750s to the early 1820s—the era of Wolfgang Amadeus Mozart, Joseph Haydn, and Ludwig van Beethoven. This section is about the specific meaning.

The Classical era established many of the norms of composition, presentation, and style, and was also when the piano became the predominant keyboard instrument. The basic forces required for an orchestra became somewhat standardized (although they would grow as the potential of a wider array of instruments was developed in the following centuries). Chamber music grew to include ensembles with as many as 8 to 10 performers for serenades. Opera continued to develop, with regional styles in Italy, France, and German-speaking lands. The opera buffa, a form of comic opera, rose in popularity. The symphony came into its own as a musical form, and the concerto was developed as a vehicle for displays of virtuoso playing skill. Orchestras no longer required a harpsichord (which had been part of the traditional continuo in the Baroque style), and were often led by the lead violinist (now called the concertmaster).^[40]

Classical era musicians continued to use many of instruments from the Baroque era, such as the cello, contrabass, recorder, trombone, timpani, fortepiano (the precursor to the modern piano) and organ. While some Baroque instruments fell into disuse (e.g., the theorbo and rackett), many Baroque instruments were changed into the versions that are still in use today, such as the Baroque violin (which became the violin), the Baroque oboe (which became the oboe) and the Baroque trumpet, which transitioned to the regular valved trumpet. During the Classical era, the stringed instruments used in orchestra and chamber music such as string quartets were standardized as the four instruments which form the string section of the orchestra: the violin, viola, cello, and double bass. Baroque-era stringed instruments such as fretted, bowed viols were phased out. Woodwinds included the basset clarinet, basset horn, clarinette d'amour, the Classical clarinet, the chalumeau, the flute, oboe and bassoon. Keyboard instruments included the clavichord and the fortepiano. While the harpsichord was still used in basso continuo accompaniment in the 1750s and 1760s, it fell out of use at the end of the century. Brass instruments included the buccin, the ophicleide (a replacement for the bass serpent, which was the precursor of the tuba) and the natural horn.

Wind instruments became more refined in the Classical era. While double-reed instruments like the oboe and bassoon became somewhat standardized in the Baroque, the clarinet family of single reeds was not widely used until Mozart expanded its role in orchestral, chamber, and concerto settings.^[41]

Major composers of this period include Wolfgang Amadeus Mozart, Ludwig van Beethoven, Joseph Haydn, Christoph Willibald Gluck, Johann Christian Bach, Luigi Boccherini, Carl Philipp Emanuel Bach, Muzio Clementi, Antonio Salieri, and Johann Nepomuk Hummel.

The music of the Romantic era, from roughly the first decade of the 19th century to the early 20th century, was characterized by increased attention to an extended melodic line, as well as expressive and emotional elements, paralleling romanticism in other art forms. Musical forms began to break from the Classical era forms (even as those were being codified), with free-form pieces like nocturnes, fantasias, and preludes being written where accepted ideas about the exposition and development of themes were ignored or minimized.^[42] The music became more chromatic, dissonant, and tonally colorful, with tensions (with respect to accepted norms of the older forms) about key signatures increasing.^[43] The art song (or Lied) came to maturity in this era, as did the epic scales of grand opera, ultimately transcended by Richard Wagner's Ring cycle.^[44]

In the 19th century, musical institutions emerged from the control of wealthy patrons, as composers and musicians could construct lives independent of the nobility. Increasing interest in music by the growing middle classes throughout western Europe spurred the creation of organizations for the teaching, performance, and preservation of music. The piano, which achieved its modern construction in this era (in part due to industrial advances in metallurgy) became widely popular with the middle class, whose demands for the instrument spurred a large number of piano builders. Many symphony orchestras date their founding to this era.^[43] Some musicians and composers were the stars of the day; some, like Franz Liszt and Niccolò Paganini, fulfilled both roles.^[45]

European cultural ideas and institutions began to follow colonial expansion into other parts of the world. There was also a rise, especially toward the end of the era, of nationalism in music (echoing, in some cases, political sentiments of the time), as composers such as Edvard Grieg, Nikolai Rimsky-Korsakov, and Antonín Dvořák echoed traditional music of their homelands in their compositions.^[46]

In the Romantic era, the modern piano, with a more powerful, sustained tone and a wider range took over from the more delicate-sounding fortepiano. In the orchestra, the existing Classical instruments and sections were retained (string section, woodwinds, brass, and percussion), but these sections were typically expanded to make a fuller, bigger sound. For example, while a Baroque orchestra may have had two double bass players, a Romantic orchestra could have as many as ten. "As music grew more expressive, the standard orchestral palette just wasn't rich enough for many Romantic composers." ^[47]

The family of instruments used, especially in orchestras, grew. A wider array of percussion instruments began to appear. Brass instruments took on larger roles, as the introduction of rotary valves made it possible for them to play a wider range of notes. The size of the orchestra (typically around 40 in the Classical era) grew to be over 100.^[43] Gustav Mahler's 1906 Symphony No. 8, for example, has been performed with over 150 instrumentalists and choirs of over 400.^[48] New woodwind instruments were added, such as the contrabassoon, bass clarinet and piccolo and new percussion instruments were added, including xylophones, snare drums, celestas (a bell-like keyboard instrument), bells, and triangles,^[47] large orchestral harps, and even wind machines for sound effects. Saxophones appear in some scores from the late 19th century onwards. While appearing only as featured solo instruments in some works, for example Maurice Ravel's orchestration of Modest Mussorgsky's Pictures at an Exhibition and Sergei Rachmaninoff's Symphonic Dances, the saxophone is included in other works such as Sergei Prokofiev's Romeo and Juliet Suites 1 and 2 and many other works as a member of the orchestral ensemble. In some compositions such as Ravel's Boléro, two or more saxophones of different sizes are used to create an entire section like the other sections of the orchestra. The euphonium is featured in a few late Romantic and 20th-century works, usually playing parts marked "tenor tuba", including Gustav Holst's The Planets, and Richard Strauss's Ein Heldenleben.

The Wagner tuba, a modified member of the horn family, appears in Richard Wagner's cycle Der Ring des Nibelungen and several other works by Strauss, Béla Bartók, and others; it has a prominent role in Anton Bruckner's Symphony No. 7 in E Major.^[49] Cornets appear regularly in 19th-century scores, alongside trumpets which were regarded as less agile, at least until the end of the century.

Prominent composers of this era include Pyotr Ilyich Tchaikovsky, Frédéric Chopin, Hector Berlioz, Franz Schubert, Robert Schumann, Felix Mendelssohn, Franz Liszt, Giuseppe Verdi, Richard Wagner, Johannes Brahms, and Johann Strauss II.

Encompassing a wide variety of post-Romantic styles, modernist classical music includes late romantic, impressionist, expressionist, and neoclassical, styles of composition. Modernism (1890–1930) marked an era when many composers rejected certain values of the common practice period, such as traditional tonality, melody, instrumentation, and structure. The high-modern era saw the emergence of neo-classical and serial music.

Modernism in music is a philosophical and aesthetic stance underlying the period of change and development in musical language that occurred from 1890 to 1930. Two musical movements that were dominant during this time were the impressionist beginning around 1890 and the expressionist that started around 1908. It was a period of diverse reactions in challenging and reinterpreting older categories of music, innovations that lead to new ways of organizing and approaching harmonic, melodic, sonic, and rhythmic aspects of music, and changes in aesthetic worldviews in close relation to the larger identifiable period of modernism in the arts of the time. The operative word most associated with it is "innovation".^[50] Its leading feature is a "linguistic plurality", which is to say that no single music genre ever assumed a dominant position.^[51]

Other prominent composers of the early 20th century include Igor Stravinsky, Claude Debussy, Dmitri Shostakovich, Sergei Rachmaninoff, Sergei Prokofiev, Arnold Schoenberg, Heitor Villa-Lobos, Anton Webern, Alban Berg, Cécile Chaminade, Paul Hindemith, Aram Khachaturian, George Gershwin, Amy Beach, Edvard Grieg, and Béla Bartók.

Postmodern music is a period of music that began around 1930.^[52][53] It shares characteristics with postmodernist art – that is, art that comes after and reacts against modernism.

Many instruments that in the 2010s are associated with popular music filled important roles in early music, such as bagpipes, theorbos, vihuelas, hurdy-gurdies (hand-cranked string instruments), accordions, alphorns, hydraulises, calliopes, sistrums, and some woodwind instruments such as tin whistles, panpipes, shawms and crumhorns. On the other hand, instruments such as the acoustic guitar, once associated mainly with popular music, gained prominence in classical music in the 19th and 20th centuries in the form of the classical guitar and banjo. While equal temperament gradually became accepted as the dominant musical temperament during the 19th century, different historical temperaments are often used for music from earlier periods. For instance, music of the English Renaissance is often performed in meantone temperament. As well, while professional orchestras and pop bands all around the world have tuned to an A fixed at 440 Hz since the late 19th century, there was historically a great variety in the tuning pitch, as attested to in historical pipe organs that still exist.^[54]

A few authorities have claimed high-modernism as the beginning of postmodern music from about 1930.^[52][53] Others have more or less equated postmodern music with the "contemporary music" composed from the late 20th century through to the early 21st century.^[55][56] Some of the diverse movements of the postmodern/contemporary era include the neoromantic, neomedieval, minimalist, and post minimalist.

Contemporary classical music at the beginning of the 21st century was often considered to include all post-1945 musical forms.^[57] A generation later, this term now properly refers to the music of today written by composers who are still alive; music that came into prominence in the mid-1970s. It includes different variations of modernist, postmodern, neoromantic, and pluralist music.^[58]

Almost all of the composers who are described in music textbooks on classical music and whose works are widely performed as part of the standard concert repertoire are male composers, even though there has been a large number of women composers throughout the classical music period. Musicologist Marcia Citron has asked "[w]hy is music composed by women so marginal to the standard 'classical' repertoire?"^[59] Citron "examines the practices and attitudes that have led to the exclusion of women composers from the received 'canon' of performed musical works." She argues that in the 1800s, women composers typically wrote art songs for performance in small recitals rather than symphonies intended for performance with an orchestra in a large hall, with the latter works being seen as the most important genre for composers; since women composers did not write many symphonies, they were deemed to be not notable as composers.^[59] In the "...Concise Oxford History of Music, Clara S[c]humann is one of the only [sic] female composers mentioned."^[60] Abbey Philips states that "[d]uring the 20th century the women who were composing/playing gained far less attention than their male counterparts."^[60]

Historically, major professional orchestras have been mostly or entirely composed of musicians who are men. Some of the earliest cases of women being hired in professional orchestras was in the position of harpist. The Vienna Philharmonic, for example, did not accept women to permanent membership until 1997, far later than the other orchestras ranked among the world's top five by Gramophone in 2008.^[61] The last major orchestra to appoint a woman to a permanent position was the Berlin Philharmonic.^[62] As late as February 1996, the Vienna Philharmonic's principal flute, Dieter Flury, told Westdeutscher Rundfunk that accepting women would be "gambling with the emotional unity (emotionelle Geschlossenheit) that this organism currently has".^[63] In April 1996, the orchestra's press secretary wrote that "compensating for the expected leaves of absence" of maternity leave would be a problem.^[64]

In 1997, the Vienna Philharmonic was "facing protests during a [US] tour" by the National Organization for Women and the International Alliance for Women in Music. Finally, "after being held up to increasing ridicule even in socially conservative Austria, members of the orchestra gathered [on 28 February 1997] in an extraordinary meeting on the eve of their departure and agreed to admit a woman, Anna Lelkes, as harpist."^[65] As of 2013, the orchestra has six female members; one of them, violinist Albena Danailova became one of the orchestra's concertmasters in 2008, the first woman to hold that position.^[66] In 2012, women still made up just 6% of the orchestra's membership. VPO president Clemens Hellsberg said the VPO now uses completely screened blind auditions.^[67]

In 2013, an article in Mother Jones stated that while "[m]any prestigious orchestras have significant female membership—women outnumber men in the New York Philharmonic's violin section—and several renowned ensembles, including the National Symphony Orchestra, the Detroit Symphony, and the Minnesota Symphony, are led by women violinists", the double bass, brass, and percussion sections of major orchestras "...are still predominantly male."^[68] A 2014 BBC article stated that the "...introduction of 'blind' auditions, where a prospective instrumentalist performs behind a screen so that the judging panel can exercise no gender or racial prejudice, has seen the gender balance of traditionally male-dominated symphony orchestras gradually shift."^[69]

Classical music has often incorporated elements or material from popular music of the composer's time. Examples include occasional music such as Brahms' use of student drinking songs in his Academic Festival Overture, genres exemplified by Kurt Weill's The Threepenny Opera, and the influence of jazz on early and mid-20th-century composers including Maurice Ravel, exemplified by the movement entitled "Blues" in his sonata for violin and piano.^[70] Some postmodern, minimalist and postminimalist classical composers acknowledge a debt to popular music.^[71]

Numerous examples show influence in the opposite direction, including popular songs based on classical music, the use to which Pachelbel's Canon has been put since the 1970s, and the musical crossover phenomenon, where classical musicians have achieved success in the popular music arena.^[72] In heavy metal, a number of lead guitarists (playing electric guitar), including Ritchie Blackmore and Randy Rhoads, modeled their playing styles on Baroque or Classical-era instrumental music.

Composers of classical music have often made use of folk music (music created by musicians who are commonly not classically trained, often from a purely oral tradition). Some composers, like Dvořák and Smetana,^[73] have used folk themes to impart a nationalist flavor to their work, while others like Bartók have used specific themes lifted whole from their folk-music origins.^[74]

Certain staples of classical music are often used commercially (either in advertising or in movie soundtracks). In television commercials, several passages have become clichéd, particularly the opening of Richard Strauss' Also sprach Zarathustra (made famous in the film 2001: A Space Odyssey) and the opening section "O Fortuna" of Carl Orff's Carmina Burana; other examples include the "Dies irae" from the Verdi Requiem, Edvard Grieg's "In the Hall of the Mountain King" from Peer Gynt, the opening bars of Beethoven's Symphony No. 5, Wagner's "Ride of the Valkyries" from Die Walküre, Rimsky-Korsakov's "Flight of the Bumblebee", and excerpts of Aaron Copland's Rodeo. Several works from the Golden Age of Animation matched the action to classical music. Notable examples are Walt Disney's Fantasia, Tom and Jerry's Johann Mouse, and Warner Bros.' Rabbit of Seville and What's Opera, Doc?

Similarly, movies and television often revert to standard, clichéd excerpts of classical music to convey refinement or opulence: some of the most-often heard pieces in this category include Bach´s Cello Suite No. 1, Mozart's Eine kleine Nachtmusik, Vivaldi's Four Seasons, Mussorgsky's Night on Bald Mountain (as orchestrated by Rimsky-Korsakov), and Rossini's "William Tell Overture". The same passages are often used by telephone call centres to induce a sense of calm in customers waiting in a queue. Shawn Vancour argues that the commercialization of classical music in the early 20th century may have harmed the music industry through inadequate representation.^[75]

During the 1990s, several research papers and popular books wrote on what came to be called the "Mozart effect": an observed temporary, small elevation of scores on certain tests as a result of listening to Mozart's works. The approach has been popularized in a book by Don Campbell, and is based on an experiment published in Nature suggesting that listening to Mozart temporarily boosted students' IQ by 8 to 9 points.^[76] This popularized version of the theory was expressed succinctly by the New York Times music columnist Alex Ross: "researchers... have determined that listening to Mozart actually makes you smarter."^[77] Promoters marketed CDs claimed to induce the effect. Florida passed a law requiring toddlers in state-run schools to listen to classical music every day, and in 1998 the governor of Georgia budgeted $105,000 per year to provide every child born in Georgia with a tape or CD of classical music. One of the co-authors of the original studies of the Mozart effect commented "I don't think it can hurt. I'm all for exposing children to wonderful cultural experiences. But I do think the money could be better spent on music education programs."^[78]

In 1996/97, a research study was conducted on a population of preschool through college students in the Cherry Creek School District in Denver, Colorado, US. The study showed that students who actively listen to classical music before studying had higher academic scores. The research further indicated that students who listened to the music prior to an examination also had positively elevated achievement scores. Students who listened to rock-and-roll or Country music had moderately lower scores. The study further indicated that students who used classical music during the course of study had a significant leap in their academic performance; whereas, those who listened to other types of music had significantly lowered academic scores. The research was conducted over several schools within the Cherry Creek School District and was conducted through the University of Colorado. This study is reflective of several recent studies (i.e. Mike Manthei and Steve N. Kelly of the University of Nebraska at Omaha; Donald A. Hodges and Debra S. O'Connell^[79] of the University of North Carolina at Greensboro) and others.

Nation-specific: