Many different kinds of melodies were developed during the 20th century.
Some impressionist music is based on whole tone scales, especially the music of Debussy. Debussy and other impressionist composers, such as Maurice Ravel, also rediscovered modes and used them to create new sound worlds that shocked audiences in the early 20th century.
In the third movement of Steve Reich’s Electric Counterpoint the original pattern is shifted a number of times to create a delayed effect.
Electric Counterpoint, Movement III
Arnold Schoenberg’s Five Orchestral Pieces is an excellent example of Expressionism. Peripetie opens with examples of all of the features listed above.
Serialism was Schoenberg’s way of changing the tonality of his music. Instead of using major and minor scales, he took each of the 12 notes of the chromatic scale and rearranged them into a new 12 tone scale. This became the tone row for the piece. The original tone scale was called the prime order. Schoenberg manipulated the prime order to make new tone rows for the same piece of music. He would transpose it, and turn it backwards (retrograde) - and upside down - inversion.
The first movement from Anton Webern’s String Quartet Op.22 is an excellent example of Serialism.
Melodies from different styles and genres came from a number of different scales:
Melodies were also decorated in alternative ways from the Western Classical tradition:
In the 20th century, composers thought about different approaches to tonality and harmony. A number of movements developed their own harmonic languages:
Some features of these styles are:
Traditional and tonal harmonic patterns were also developed, such as the 12-bar blues.
Expressionist music was extremely dissonant. Diatonic chords were rarely used and there were very few, if any, clear cadences. Listen to Arnold Schoenberg’s Peripetie from his Five Orchestral Pieces.
Schoenberg also developed a new system to replace tonality in his music. This was called serialism. Instead of using major and minor scales, Schoenberg took the 12 tones of the chromatic scale and reordered them in any way he wanted. He would then base his composition on this rearranged tone row. The tone row would be manipulated throughout the piece - including being played backwards and upside down. An example of serialism can be found in Schoenberg’s Pierrot Lunaire.
As well as creating extreme dissonances, some composers wrote music that included microtones - intervals smaller than a semitone. The sound came across to the listener as dissonance. Quarter tones, or half a semitone, were also used. They are a type of microtone. Béla Bartók and Charles Ives both used microtones in their music. Listen to Bartók’s Sonata for Violin - ssz 117- to hear this effect.
In modern popular music, tonality and harmony are simple. The 12-bar-blues chord sequence became the foundation of rock ’n’ roll music.
You can hear an example of 12-bar blues style in Bill Haley and his Comets’ Rock around the Clock.
As with other musical elements, the early 20th century was a time when structure and form were developed in many different ways. A number of forms evolved in popular and world music traditions.
This form was popular in rock ’n’ roll, and was originally the basis of blues music.
The structure of verse-chorus became the foundation for 20th century popular music. A chorus was the section that was repeated and had the same music and words. Verses had the same music but different lyrics. Within this structure, songwriters also included intros and outros, the middle 8, instrumental breaks and bridges between verses and choruses.
What is known as the 32-bar structure became popular in early 20th century US popular music, and can be found in many of George Gershwin’s and Cole Porter’s songs. The form is AABA, each section being eight bars long. A famous example is Over the Rainbow by Harold Arlen.
The History of Electronic Music in 476 Tracks (1937-2001)
http://www.openculture.com/2016/03/the-history-of-electronic-music-in-476-tracks-1937-2001.html
100 Years of Rock
Interactive Site with listening examples