We have come to place music into two broad categories; that of New Music and that of Traditional Music. Music before the turn of the century has come to be thought of as the Traditional. This Traditional Music gets lumped together in what most people refer to as Classical. This classification is so well fixed in people’s minds that even traditional rock music is referred to as Classic Rock.
The so called Classical Music is really about three different periods that were all different in their practice. Even so, there are some differences in the music after the turn of the century that are distinctive enough to warrant the label of New Music.
Prior to the turn of the century, all music was ‘goal oriented’ or ‘tonal,’ meaning that there was one chord in the particular composition that was the goal or resting point of the music’s chord progression. When this chord was reached, the music sounded finished and the music would not sound finished until this chord was reached. Hence this chord would show-up at the very end of the music but also at the ends of all phrases or melodies, pretty much. It would not be the same chord for every piece of music but would depend on the ‘key’ of the music. That is the meaning of ‘key.’ If a piece of music is in the ‘key of C,’ then the chord it must end on is C. A work in the ‘key of G’ would end on G and so forth.
Well. after a hundred years or so, composers got the itch to try something new and so we find the first examples of the New Music. Claude Debussy has often been called the ‘Father of Modern Music,’ and his works began to make tonality ambiguous by employing other types of scales such as the Whole Tone Scale.
Some composers went beyond this and tossed out tonality all together. The most notable example of this was the Serial Music composed by Arnold Schoenberg. Serial Music used a scale of twelve tones (rather than the traditional eight) and studiously avoided any note/chord relationship. Some other composers like John Cage created what was called ‘Chance Music,’ where the notes in the piece were determined by the throw of dice.
Meanwhile, at this same time, jazz was being made. Jazz and Blues returned to tonality with a vengeance. However there were many other elements added that qualified this as New Music. The difference in instrumentation, with the electric guitar and the greatly expanded role of the drums were certainly things that had not gone on before and so the birth of jazz and its development into the pop of today certainly fits into the category of New Music.