What is the name of the team song written by ken walther?
CREATE TABLE "notes" (
  "club_name" text,
  "name_of_team_song" text,
  "basis_for_team_song" text,
  "first_used_as_team_song" text,
  "writer_composer" text
);
SELECT "basis_for_team_song" FROM "notes" WHERE "writer_composer"='Ken Walther';