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_28715942_5 (track VARCHAR, vocal_percussionist VARCHAR)
### Question:
What is the track whent the vocal percussionist is unknown?
### Answer:
SELECT track FROM table_28715942_5 WHERE vocal_percussionist = "unknown"