The 20th century saw a radical shift in the language of music. Composers sought ways to break away from the conventional major/minor system of harmony and melody and adopted a less constrained (though by no means less organised) approach to composition. Composers began using new types of scale, would compose in several keys simultaneously or no key at all, and looked for new ways to organise music. A generous serving of chromaticism was the hallmark of 20th century music, with works like Stravinsky’s Rite of Spring sparking riots because of it’s liberal use of dissonance and unconventional harmonic and melodic writing. (Of course the Rite of Spring seems quite tame by today’s standards.) This move began with the impressionist composers and from there branched into several diverse schools.
Music of the twentieth century can be divided into two quite distinct periods, before World War II and after World War II. Prior to WWII composers began looking for ways to move away from what they saw as the excesses of romanticism. The two main schools that arose at this time were Neo Classicism, and Expressionism.
The neo-classical composers such as Igor Stravinsky and Dimitri Shostakovich looked back to the abstract music of the classical period while incorporating new approaches to harmony, melody, and counterpoint. For the neo-classicists like Stravinsky, music was “incapable of expressing anything” and so – as was the case for composers in the classical period – melody, harmony, form, and thematic development were all important.
Expressionist composers, on the other hand, felt the opposite. For them, music was about the depiction of the emotional and psychological states of the modern person. The kinds of emotion and the means used to express it in expressionist music were different, however, from those of romantic composers. Expressionist composers like Arnold Schoenberg, Alban Berg, and Anton Webern didn’t seek to invoke an emotional response in the audience, as much as depict, musically, a particular emotion or psychological state – which included emotions like fear, anxiety, hopelessness and the irrational drives of the subconscious that would have been of interest to Schoenberg’s fellow-Viennese Sigmond Freud.
Another significant development in music at this time which shouldn’t be overlooked was Jazz. Jazz was the invention of African-Americans and came about largely by combining elements of European classical music with African based music. Jazz is a significant movement in itself but also proved to be a rich source of ideas and inspiration for non-jazz composers such as Maurice Ravel and Dimitri Shostakovich among a plethora of others.
The developments that occurred in music after the second world war where just as radical, and even more diverse, than those that came at the turn of the century. Composers began to not only push the boundaries of how music could be written, but also of what constituted “music.” One of the most extreme examples of this new breed of composer is John Cage whose 4’33” consists of a performer siting silently for 4 minutes and 33 seconds. Other more extreme developments include indeterminacy – where music would be composed by random means such as rolling dice – and graphic notation, in which traditional notation was replaced by lines, shapes, and other markings which often had no precise meaning but would be interpreted by the performer at the time of performance.
However, these new developments are just a sample of what composers began doing in the second half of the 20th century. Music of the late 20th century was more diverse than in any other period preceding it. While some composers continued pushing boundaries, other began to look back to the classical and romantic periods. Others looked to Jazz and popular music for inspiration and many began to explore the possibilities of electronic and computer generated music.