Complex sentence: Described as "the theatre's greatest living poet" since Samuel Beckett, Müller is arguably the most important German dramatist of the 20th century after Bertolt Brecht, and his "enigmatic, fragmentary pieces" are a significant contribution to a postmodern drama.
Split into simpler sentences: Described as "the theatre's greatest living poet" since Samuel Beckett, Müller is arguably the most important German dramatist of the 20th century after Bertolt Brecht. His "enigmatic, fragmentary pieces" are a significant contribution to postmodern drama.