What is the musical lottery Paul gambles on in his two-year plan?

From the text:

A Two Year Plan. I had bargained for it with my parents—who finally agreed, impressed by my performances and exam results. They even put up the larger share of the money, mortgaging their new home. One year to learn the ropes, I argued: one year to become a familiar face, a fixture, and a second year to see how far I could go. It was a gamble, of course—a musical lottery, Keller had often called it—but a lottery whose odds could be shortened, and whose First Prizes meant Instant Career. I realised even then that I would have regretted all my life not taking that gamble. As also—despite their doubts—would my parents. They had wanted a concert pianist in the family for years. The Dream would have itched away at them, lingering, nagging, still possible. Could he have? What if?