Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_2414_1 (reference VARCHAR, violas VARCHAR, author VARCHAR)
### Question:
What reference, written by Nelson Riddle, suggests 2 violas?
### Answer:
SELECT reference FROM table_2414_1 WHERE violas = 2 AND author = "Nelson Riddle"