Simplify the following text for a Grade 12 native English-speaking person.
Original: Fischer-Dieskau also performed many works of contemporary music , including Benjamin Britten , Samuel Barber , Hans Werner Henze , Karl Amadeus Hartmann ( who wrote his Gesangsszene for him ) , Ernst Krenek , Witold LutosÅ awski , Siegfried Matthus , Winfried Zillig , Gottfried von Einem and Aribert Reimann .
Simplified: Fischer-Dieskau also performed many works by living composers including Benjamin Britten , Samuel Barber , Hans Werner Henze , Karl Amadeus Hartmann , Ernst Krenek and Witold LutosÅ awski .