What are the names of Art instructors who have taught a course, and the corresponding course id?
SELECT name ,  course_id FROM instructor AS T1 JOIN teaches AS T2 ON T1.ID  =  T2.ID WHERE T1.dept_name  =  'Art'
Art instructors refers to instructors in the Art department; names and corresponding course id refers to selecting both the instructor's name and the course id they have taught; taught a course is represented by a JOIN between instructor and teaches tables on instructor ID.