It used to be that, as a musician, only 10% of your career was up to you. “Getting discovered” was about all you could do. A few gatekeepers controlled ALL outlets. You had to impress one of these magic few people to be allowed to present your music to the world. (Even then, they assigned you a manager, stylist, producer, band, etc.)
As of the last few years, now 90% of your career is up to you. You have all the tools to make it happen.
Record labels aren't guessing anymore. They're only signing artists that have made a success on their own. As Alan Elliott says, “A record label used to be able to look at a tree and say, 'That would make a great table.' Now all they can do is take a finished table and sell it at Wal-Mart.”
You have to make a great recording, a great show, a great image. You have to come up with a plan and make it happen, too. You have to make thousands of people want your music so much they pay good money for it. You have to make things happen on your own. Even if a record label puts it in the stores for you, it's still up to your own hard work to go make people buy it.
The only thing stopping you from great success is yourself. This is both scary and exciting. At least you're in control.