Question: Who was mentored by Arnold Schoenberg and worked on the album "At the Grave of Richard Wagner"?
Sentence (from "Anton Webern"): Along with his mentor Arnold Schoenberg and his colleague Alban Berg, Webern was at the core among those within and more peripheral to the circle of the Second Viennese School, including Ernst Krenek and Theodor W. Adorno.
Relevant evidence: Yes