Who was the director of the movie having a release date of 1934-09-15, an MM Series and a production number less than 6494?
CREATE TABLE "1934" (
  "title" text,
  "series" text,
  "director" text,
  "production_num" real,
  "release_date" text
);
SELECT "director" FROM "1934" WHERE "series"='mm' AND "production_num"<6494 AND "release_date"='1934-09-15';