Not everyone who takes piano lessons can play the piano well. Karma and physical condition can come into play.
As to the master question it probably arose from the traveling of early Buddhist monks from India. In ancient times enlightenment and various healing & other siddhi powers were passed from master to student. This is called diksha. The diksha is like a seed. And the growth of a seed is very dependent upon many factors, among them the soild and how it was planted. There is no gurantee that a diksha will impact a being-oft times it will lay dormant.
