Music in the 20th century

In the 20th century, composers broke the old rules: new scales, clashing chords, irregular rhythms and even silence.

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Impressionism

Claude Debussy (1862 to 1918) was a French composer often linked with Impressionism, named after the painters who suggested light and atmosphere rather than sharp detail.
His music has blurred, shimmering textures, unusual chords and scales such as the whole-tone scale (made only of tones, for example C D E F# G# A#) and the pentatonic scale.
A famous example is his Prelude to the Afternoon of a Faun (1894).

Rhythm and dissonance

Igor Stravinsky (1882 to 1971) wrote the ballet The Rite of Spring. Its first performance in Paris in 1913 caused an uproar in the audience. It uses irregular rhythms, changing time signatures, heavy accents and harsh dissonance.
Arnold Schoenberg (1874 to 1951) wrote atonal music (music with no key) and developed serialism: all 12 notes of the octave are put in an order called a tone row, and used in that order.

More new ideas

Jazz influenced concert music, as in George Gershwin's Rhapsody in Blue (1924).
The British composer Gustav Holst wrote The Planets; its first movement, 'Mars', is in 5/4 time.
Benjamin Britten wrote The Young Person's Guide to the Orchestra, which introduces each family of the orchestra in turn.
John Cage wrote 4'33" (1952), in which the performer plays nothing: the music is the sounds of the room.
Worked example

A piece has no clear key, all 12 notes used in a fixed order, and lots of dissonance. Which 20th-century technique is it?

  1. No key means the music is atonal.
  2. All 12 notes used in a fixed order is a tone row.
  3. Writing music from a tone row is serialism, developed by Schoenberg.

Answer: Serialism (atonal music built on a tone row), developed by Schoenberg.

Key idea

20th-century music: Debussy and Impressionism (whole-tone scale); Stravinsky's The Rite of Spring (1913) with irregular rhythms and dissonance; Schoenberg's atonality and serialism (tone rows); jazz influence; Cage's 4'33".

Key words
Dissonance
Notes that clash and sound tense.
Tone
A step of two semitones.
Pentatonic scale
A scale of five notes, such as C D E G A.
Atonal
Music with no key or home note.
Octave
The distance from one note to the next note with the same letter name, 12 semitones.

All KS3 Music key terms and definitions →

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  1. Which feature is typical of Impressionist music?

    1. Strict counterpoint
    2. Alberti bass
    3. A 12-bar blues pattern
    4. Shimmering, blurred harmonies that create atmosphere
    Show the answer

    Answer: Shimmering, blurred harmonies that create atmosphere

    Impressionism paints moods in sound.

  2. How many notes are in a whole-tone scale?

    1. 7
    2. 5
    3. 6
    4. 12
    Show the answer

    Answer: 6

    Six tones fill the octave.

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Last updated 2 October 2026. Spotted a mistake? Tell us and we will fix it.