Lucky is usually the wrong word. I think chance and probability are usually more fitting.
It may be only a one in a hundred chance of getting that big promotion, getting funded, or getting that album deal. The successful one works tirelessly, practices night and day, tries and fails repeatedly, all to increase the chance of her making it.
A lucky person takes on risk in pursuit of their goal. A lucky person intentionally works on their craft. A lucky person gets up before everyone else, to take themselves one inch closer.
There are always a number of factors that go into success: privilege, hard work, smart work, probability, and chance. Luck makes up none of it.