"The purpose of this paper is to explore the transition from a Romantic, Brahmsian style to chromaticism in Schoenberg's chamber music writing style with emphasis on tonal relationships. The String Quartet in D Major (1897) was selected as a starting point because it was his first important work to be performed in public and is not at all characteristic of his later writing. It will be contrasted with his sextet, Verklarte Nacht (1899), Op. 4, a pivotal composition that shows a great deal of chromaticism. An analysis of the form and tonal relationships of both pieces and a comparison to common practices as outlined in textbooks and established examples of the genre realizes the expected result. The String Quartet in D Major conforms to standard key relationships and to sonata form compositional practices for both structural and chordal analyses. The forms are easily recognizable and well emphasized by the profuse use of dynamic markings and the texture of the part writing. Throughout the work, Schoenberg appropriates devices used by romantic composers such as Brahms and Dvorak. Brahms' influence on this composition are evident in structure, melodic and rhythmic devices and instrumental color. Verklarte Nacht presents a more interesting analysis. It is an amalgamation of chamber music and program music and is based on the poem of the same name by Richard Dehmel (1863-1925). Verklarte Nacht provides one with a view of Schoenberg's development as a composer and the direction his subsequent work was to take. He is no longer bound by sonata form and rules of thematic development as he seemed to be when he wrote his String Quartet in D Major. Themes are not developed strictly according to sonata form with clear transitions and modulations. Thematic development is more chromatic and themes are closely related to each other and to the form of the poem. Schoenberg's writing now begins to show the influence of Richard Wagner's in his thematic development, instrumental usage, and in the way the music expresses the action and emotion of the poem. This paper concludes that Schoenberg developed his compositional style in terms of both style and tonality from Romantic form and tonality typical of Brahms to a more chromatically saturated style with less adherence to strict forms. He moves away from 18th-century conventions of tonality toward free tonality. These works show the composer's progression from Romantic German formal part writing with conventional tonal relationships to a looser form more dependent on thematic material and programmatic agenda using increasingly chromatic harmonies and melodies"--Document.