20th-century classical music

20th-century classical music is classical music written during the last century. During earlier periods of music history composers from different countries wrote in styles which were often quite similar. For example, composers in the Classical music period (about 1740-1820) had fairly similar ideas about what forms to use (e.g. sonata form), what instruments should be used in orchestras or how to write good tunes.
Classical music from the 20th century is extremely varied. There are lots of different "schools" (meaning: ways of thinking) as lots of composers had their own ideas about how to compose in ways that were different from what had been done before. A lot of these genres (types of music) had names ending in "ism": there was serialism, Expressionism, Neoclassicism, Impressionism as well as jazz, world music (music from non-European cultures) and folksong and, later on electronic music and then Minimalism and even post-modernism.
The names of periods in history were usually given to them many years afterwards. For example, the term Middle Ages was not used until long after the Middle Ages had finished. It is difficult to know what to call the period we live in now. In music people often talk about "Modern Music" meaning any music written after 1900. We also talk about "Contemporary Music" meaning more or less the same thing ("contemporary" means "things that are happening in our time", i.e. "living composers"). Now that the 21st century has started some musicians are starting to talk about "20th century music" (1900-2000) and a period called "Contemporary Music" (1975-today).
This article will discuss classical music written from 1900 to the year 1999.
Reaction to Romanticism
Many European composers at the beginning of the 20th century felt that the system of tonality (music in major and minor keys) had been used for so long that it was time to do create a new approach and try something different. Arnold Schoenberg and Igor Stravinsky were two of the most important composers at that time, and they had very different ideas about how to compose music.
Schoenberg's music became very atonal (not in any key). Eventually he developed what he called twelve tone music. This was atonal music which was organized by putting the notes of a musical idea in a particular order which could be changed in many ways during the piece. This way of organizing music is called "serialism" (a "series" is a "row of things"). Many composers were influenced by Schoenberg, especially Alban Berg and Anton von Webern.
Stravinsky came from Russia. He was inspired by Russian culture. He wrote some music for a ballet called Rite of Spring. This music was very new. It had very irregular rhythms which the dancers found very difficult to dance to at first. It also used polytonality (being in more than one key at once). Later on Stravinsky was inspired by music from the 18th century. He used it, but made changes to it, adding dissonant notes and strange chords. This is called neoclassicism ("neo" means "new"). Stravinsky's music seemed to many people to be the opposite of serialism, but in his last years Stravinsky started to use serialism as well.
Impressionism
In France a movement called Impressionism was popular with painters. Composers were very interested in these paintings. Claude Debussy wrote music which is often called "Impressionistic". The ideas of clear tonality (being clear about which key the music is in) are often deliberately blurred. He uses interesting chords just for the sound that they make. He used the whole tone scale and pentatonic scale and was inspired by Javanese music. Maurice Ravel's music is sometimes similar, although he developed his own style. Later French composers include Olivier Messiaen who used a system of new scales which he called Modes of limited transposition. He was also interested in music from around the world, and he also used bird song in his music.
Late Romanticism
While all this was happening there were some composers who continued to write in a style which was basically Romantic. Edward Elgar 's music is often described as "Edwardian" (from the period of King Edward VII). Other British composers of the time were also inspired by English folkmusic, i.e. Ralph Vaughan Williams, George Butterworth, Roger Quilter and Gerald Finzi. Frederick Delius wrote Romantic music which was also quite Impressionistic. The Russian Sergei Rachmaninoff and the German Richard Strauss continued to write in a Romantic style until their deaths in the 1940s. The Finnish composer Jean Sibelius and the Dane Carl Nielsen wrote great symphonies which were still in a tonal style, and in Italy Puccini was writing operas in a Romantic style, often called "verismo" ("like real life").
Symphonic tradition
In Russia, which became the Soviet Union after the 1917 Revolution, composers were not allowed to be experimental. It was difficult for them because they had to please the politicians who told them that their music should reflect "Socialist realism" (meaning the workers' struggle against capitalism). The great tradition of writing symphonies continued with Sergei Prokofiev (who spent some time in exile) and Shostakovich (who remained in the Soviet Union).
The Hungarian composer Bela Bartok developed a modern style influenced by folk music from his country and other East European countries. His music is often quite neoclassical, for example the famous Concerto for Orchestra.
Avant garde experiments
In the mid-20th century a group of composers known as the "Darmstadt School" (because they often met in Darmstadt) continued to write music which was based on serialism. This included Pierre Boulez and Karlheinz Stockhausen. Many of them, including both Boulez and Stockhausen, also experimented with electronic music. The term Avant Garde is often used to describe their music. It means that it expands the limits, or pushes ahead into new ground (literally the "front guard", a military analogy). Other American composers were experimental, e.g. Charles Ives and John Cage who is famous for using a "prepared piano" (a piano which makes strange sounds because strange objects are put inside it).
Jazz influence
In America jazz was a big influence on classical composers. George Gershwin's music is halfway between jazz and classical. Aaron Copland and Leonard Bernstein used jazz elements in their music. In Europe many composer used ideas from jazz, e.g. Maurice Ravel and Kurt Weill.
Minimalism
Around the 1960s some composers thought that a lot of music was getting too complicated. Music of the avant garde school such as Edgard Varese, Elliott Carter, Milton Babbitt was becoming too difficult for people to understand. People found it too mathematical and intellectual. They wanted music with feeling and emotion. A group of composers developed a style called Minimalism which uses music based around a simple idea which repeats itself again and again but gradually changes. Steve Reich, Philip Glass, Terry Riley, John Cage and to some extent John Adams all used minimalist techniques. It was a reaction against music that had become too complicated.
Other paths based on tradition
While all these different schools of thought were coming and going there were still some composers who managed to keep to a more traditional path and find new ways to use tonality in their music. The greatest figure in British music was Benjamin Britten who was an eclectic composer (i.e. he took ideas from many different people). Two other great composers were Michael Tippett and William Walton, who each developed their own style. In America there were composers such as Samuel Barber, Roy Harris and Alan Hovhaness. In Germany Paul Hindemith was one of the most important composers. Like Kurt Weill, he often wrote music which had a political purpose, but Weill's music is more jazz-inspired.
Some contemporary composers (alive today) write music which is deeply religious. These include John Tavener and Arvo Part. John Rutter and Bob Chilcott, who write music for choirs which sounds fresh and attractive to new audiences. Other composers have found various ways of creating their own style, e.g. the Scottish composers James MacMillan and Judith Weir and the Master of the Queen's Music: Sir Peter Maxwell Davies. In Russia Sofia Gubaidulina and Galina Ustvolskaya are important voices in the search for new music.