What is the theme where the original artist is AC/DC?
CREATE TABLE "table1_25374338_1" (
  "episode" text,
  "theme" text,
  "song_choice" text,
  "original_artist" text,
  "order_num" text,
  "result" text
);
SELECT "theme" FROM "table1_25374338_1" WHERE "original_artist"='AC/DC';