Question: Wilhelm von Lenz, was a Baltic German Russian official and writer, and was a friend of many mid-century Romantic composers, including Hector Berlioz, that died on which date, was a French Romantic composer, best known for his compositions "Symphonie fantastique" and "Grande messe des morts" (Requiem)?
Sentence (from "Hector Berlioz"): His influence was critical for the further development of Romanticism, especially in composers like Richard Wagner, Nikolai Rimsky-Korsakov, Franz Liszt, Richard Strauss, and Gustav Mahler.
Relevant evidence: No