user: ### NOW ANSWER:
Question: When Interplanet Janet is the episode title who is the music by?
Columns: ['Episode title', 'Subject', 'Music by', 'Performed by', 'First aired']
Types: ['text', 'text', 'text', 'text', 'real']
Sample row: ['The Body Machine', 'Nutrition and digestive system', 'Lynn Ahrens', 'Bob Dorough and Jack Sheldon', 1979.0]
SQL:

assistant: SELECT "Music by" FROM "Table" WHERE "Episode title" = 'Interplanet Janet';