Sommerwild and Kinkel are among the characters that the protagonist blames for his abandonment for Heribert Zupfner by his lover Marie Derkum.  
One character in this work is ignored by the passersby when he sits on the steps of a train station and sings his improvised song "Poor Pope John", and that character calls himself a "Jewish Yankee" to insult his mother after his sister in killed on antiaircraft duty.  The protagonist is outraged when he reads about the honors bestowed on a man who had accused him of being a defeatist and led the local Hitler Youth group during World War II, Herbert Kalick.  Sommerwild and Kinkel are among the characters that the protagonist blames for his abandonment for Heribert Zupfner by his lover Marie Derkum.  Beginning with Hans Schnier injured after performing his act while drunk, FTP, name this novel by Heinrich Boll.
One character in this work is ignored by the passersby when he sits on the steps of a train station and sings his improvised song "Poor Pope John", and that character calls himself a "Jewish Yankee" to insult his mother after his sister in killed on antiaircraft duty.  
The Clown or Ansichten eines Clowns