Going to school or learning from people in the business can help dramatically. You can learn the principles of marketing in general, and also branch into pricing and distribution and how exactly to brand yourself in the industry. Without this knowledge getting in is a lot harder than it has to be.
Learning from entrepreneurs in the business allows for the ability to ask real world questions and get answers that are not standard textbook answers. That information is key to moving along and learning the music marketing strategies that are essential to success.
Take a second and THINK about this. Many musicians get stuck in this mindset of "being a sell out" if they want to make money with their music.
That is complete rubbish. If you're staying true to your music while making money, there is NOTHING wrong with that. You're a sell out when you start to compromise your integrity.
It is absolutely possible to respect the business side of the industry while continuing to make great music. The problem we're focusing on today is the people who make great music but are still stuck at some 9-5 they know they don't want to be at anymore.