What school is a group of composers, interpreted by the soprano Alessandra Marc and was initially characterized by expanded tonality and Schoenberg's own evolution? 
Alessandra Marc: Alessandra Marc (born July 29, 1957) is an American dramatic soprano who has appeared at many of the world's opera houses and orchestras. Alessandra Marc:  Marc is particularly known for her interpretations of the works of Richard Strauss, Richard Wagner, Giuseppe Verdi, music of the Second Viennese School, and the title role in Puccini's "Turandot". Second Viennese School: The Second Viennese School (German: Zweite Wiener Schule, Neue Wiener Schule ) is the group of composers that comprised Arnold Schoenberg and his pupils and close associates in early 20th century Vienna, where he lived and taught, sporadically, between 1903 and 1925. Second Viennese School:  Their music was initially characterized by late-Romantic expanded tonality and later, following Schoenberg's own evolution, a totally chromatic expressionism without firm tonal centre, often referred to as atonality; and later still, Schoenberg's serial twelve-tone technique.
Second Viennese School