Premise: Wilhelm Killmayer (21 August 1927 – 20 August 2017) was a German composer of classical music, a conductor and an academic teacher of composition at the Hochschule für Musik und Theater München from 1973 to 1992. He composed symphonies and song cycles on poems by Friedrich Hölderlin, Joseph von Eichendorff, Georg Trakl and Peter Härtling, among others.
Hypothesis: Wilhelm Killmayer has a great-grandfather who was a duke.