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 "Wilhelm von Lenz"): Lenz promoted the idea (already suggested by earlier figures such as François-Joseph Fétis) that Beethoven's musical style be divided into three characteristic periods.
Relevant evidence: No