SCHEMA:
CREATE TABLE GENRE (GenreId VARCHAR, Name VARCHAR); CREATE TABLE TRACK (UnitPrice INTEGER, GenreId VARCHAR)
USER:
What is the average unit price of rock tracks?

QUERY:
SELECT AVG(T2.UnitPrice) FROM GENRE AS T1 JOIN TRACK AS T2 ON T1.GenreId = T2.GenreId WHERE T1.Name = "Rock"