The twentieth century is filled with many strange and fascinating new trends in the world of music, pioneered by many creative composers who dared to challenge the status quo. Claude Debussy, however, can be considered the father of modern music because many of the artistic ideas present in these new styles can be directly related back to the new ideas and expressions used by Debussy. The influence of Debussy's use of unusual sounds, his idea of indulging in the here and now, and his use of harmonies as a vehicle for emotional symbolism can be seen in many of the new musical stylistic trends that emerged in the twentieth century.
Debussy's use of unusual sounds laid a foundation for composers of avant-garde music who came after him. In his music, Debussy incorporated many exotic scales and harmonies from the Far-Eastern musical traditions for a specific artistic purpose—that being to create an atmosphere and an image in the listener's minds. Likewise, avant-garde composers such as George Crumb and Krzysztof Penderecki used this same notion of using new sounds for artistic purposes in their own works, though instead of using exotic scales, they used unusual and un-traditional methods of playing instruments—bowing on the opposite side of the bridge of a stringed instrument, for example—in order to create a mood or atmosphere, as can be seen in their works Black Angles and Threnody to the Victims of Hiroshima, respectively. These composer's ideas about the use of exotic sounds is a direct parallel to Debussy's intentions for using exotic scales and harmonies, thus, it could be said that the avant-garde composers owe a debt to Debussy.
Many composers of the mid-twentieth century began to write music in such a way that the audience was meant to simply enjoy the sounds of the music for its own sake in the here and now, not for the sake of long-past traditions. Debussy used this notion in his works as a contrast to the music of Wagner, which he believed to be too heavily rooted in the philosophies and mythologies of times past. Debussy's use of motifs was meant to appeal to the human senses of pleasure and indulgence; that is to say, he wishes for the listener to enjoy the music as it happens; right here, right now. A parallel can be made to the way composers such as John Cage used the element of chance in their music, though it could be said that Cage's use of chance takes the notion of enjoying the music as it happens to an extreme. Cage used chance to attain the same appreciation of the here and now that Debussy sought—for what better way for music to be as “here and now” as possible for it to essentially be composed—by chance—at the very last second, heard for what it is one time and never again, thus causing the audience to form a greater appreciation for it. Debussy's idea of enjoying music "here and now" laid a foundation for the style of chance music.
Though the trend of minimalism began a good sixty or so years after Debussy's time, his ideas in regards to harmonic purpose can still be seen. Debussy used harmony in his music as a tool to set a certain artistic mood, atmosphere, or color; as such, harmony was meant to appeal to the human senses more-so than the sense of musical function that dominated the use of harmony previously. As far as minimalism is concerned, this very same idea on harmony was used by John Adams in order to make the style more accessible and more enjoyable for his audiences; he also added in varied harmonies for the purpose of creating emotions and colors in his works, thus allowing the audience to connect with the music on a deeper level, making it more enjoyable. If not for Debussy's innovative ideas on harmony, minimalism may not have been able to withstand the test of Time as it has.
The styles of minimalism, chance, and the avant-garde owe a great debt to Debussy. Even though the works themselves sound nothing like Debussy's, they all draw heavily upon the conceptual ideas that he used. These influences have enhanced modern music, and have helped them to reserve their places in history and to be considered timeless.