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 fur Musik und Theater Munchen from 1973 to 1992. He composed symphonies and song cycles on poems by Friedrich Holderlin, Joseph von Eichendorff, Georg Trakl and Peter Hartling, among others.

Can we draw the following conclusion?
Killmayer taught composition in 1990.
Yes