CREATE TABLE "table1_27823359_1" (
  "series_num" real,
  "season_num" text,
  "title" text,
  "directed_by" text,
  "written_by" text,
  "original_air_date" text,
  "u_s_viewers_millions" text
);

Question: Who wrote episode 23 in the season?
SQL: SELECT "written_by" FROM "table1_27823359_1" WHERE "season_num"='23';

Question: Who wrote the episode titled "An Old-fashioned Piano Party"?
SQL: SELECT "written_by" FROM "table1_27823359_1" WHERE "title"='\"An Old-Fashioned Piano Party\"';