Question: Who is the paternal grandfather of Katharina Wagner?
Sentence (from "Katharina Wagner"): Her directorial début at the Bayreuth Festival, staging a production of Richard Wagner's "Die Meistersinger von Nürnberg" in July 2007, was booed at its premiere, but established a following which returned to watch the production evolve as Wagner made changes in each of the five years
Relevant evidence: No