Debussy’s influence on symphonic music is remarkable because the composer changed the approach to combining melodies, tones, and textures radically, while supporting his unique vision with the focus on orchestration. Returning to Haylock’s words about the important role of Debussy as an Impressionist composer, it is possible to explain why the methods used by Debussy to compose the String Quartet were discussed as both radical and based on Impressionist ideas (Haylock 100). It is important to state that the String Quartet was composed during the period important for Debussy because of his experiments with new harmonies, forms, and modalities (Lelutiu 334). In spite of the fact that Debussy rejected being discussed as an Impressionist composer, he paid much attention to reflecting the main traditions of Impressionism in his music, as it can be noticed with the focus on the String Quartet’s sound and harmonic language (Trezise 5). As a result, Debussy followed the Impressionist ideas in his music without accentuating them clearly (McFarland 296). Characteristic patterns are identified in the String Quartet as a result of the close analysis of Debussy’s harmonic language, progression, and unique use of chords. Mixed timbres are used by Debussy in the context of various forms, and their combination makes researchers speak about the uniqueness of the String Quartet as composed according to the Impressionistic music patterns (Fulcher 54; Morrison 311). From this perspective, the String Quartet can be discussed as a manifest of the Impressionist shift in Debussy’s music as well as in his unique composition method which affected the generation of composers and tendencies in symphonic music. Discussing the consequences of analyzing Debussy’s String Quartet, it is important to note that Debussy’s music was a challenge for his contemporaries, but his almost radical rejection of the traditional musical language attracted the attention of the other composers and the public. Having identified the elements of Debussy’s style, it is possible to explain the uniqueness of the composer’s music and his influence on the other composers. Debussy’s approach to composing music was discussed as distinctive by many contemporaries interested in the progress of symphonic music. Thus, Maurice Kufferath , a Belgian critic, pointed at the impossibility to make quick conclusions about Debussy’s music in the context of the Impressionists’ impact. Kufferath notes, “Where this school will lead us, what it will amount to, is difficult to predict – and that is not our business”; and he continues that it will be “the pressing concern of our descendants, who will likely scorn us as old fogies for our inability to comprehend Debussy, just as we once disdained those of our predecessors who could not come to terms with Wagner” (qtd. in Code 287). The significance of this work is in the fact that its findings are important to determine the perspectives for the further research on Debussy’s role in the history of symphonic music. The provided analysis of details regarding Debussy’s music and the Impressionistic patterns used in the String Quartet’s composition, harmony, and language are important to understand how Debussy applied the Impressionist ideas in his work and how he influenced the next generation of composers. Debussy’s hybrid music