user: Question: 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?
Columns: ['Title', 'Series', 'Director', 'Production Num.', 'Release date']
Types: ['text', 'text', 'text', 'real', 'text']
Sample row: ['Buddy the Gob', 'LT', 'Friz Freleng', 6125.0, '1934-01-13']
SQL:

assistant: SELECT "Director" FROM "Table" WHERE "Series" = 'MM' AND "Production Num." < 6494.0 AND "Release date" = '1934-09-15';