Building a successful music career is progressive. You won't get rich and famous overnight. However, you also won't be successful if you sit on your ass all day without taking action to grow your career.
As an independent musician, it takes more than just creating music to become successful. There are 5 steps in the music industry that you must take in order to be successful independently.
This is the whole point of pursuing a music career. It is you having a love for creating and performing music. If you don't enjoy music, then why are you wanting to be in the music business? Switch career choices or go back to a 9-5!
So now you have your music created and ready to perform, but what next? Branch out. Start performing gigs and going on tours. In order to do this though, you will need management. At first, you will probably only have one manager to do multiple tasks but as you progress more, you will need a management team that takes care of tasks separately such as financial, booking, promotion, etc..
You are a musician, so this means that you don't need to be a business person right? Wrong. Music marketing is a must if you want to be successful in the music industry. You don't need to go to business school for this though. You just need to learn your market. If you don't already have a management team to deal with promotion, then you must be able to know how to promote your music yourself.
However if you do have a manager that deals with promotion then music marketing should be easier. This doesn't give you a free pass though. You still need to learn some music marketing since you're on top of the management pyramid.
Starting out as an indie artist, you probably don't have a manager yet. So in able to make some money yourself, there are different ways available. The most important aspect of making music money is retailing and licensing your music. This is important for the long run.
Another obvious way to make money with your music is to perform gigs. It can produce short-term or long-term income but it all depends on your band's popularity.
This is the point of your music career where you're playing at larger venues in different cities while still growing your fan base. This doesn't mean that you have to be as big as the mainstream artists making millions with their crappy pop music.
Once you achieved the mass appeal step, start celebrating. Things only get easier from here. Fans will do the promotion for you and reach out to new fans who will then make you money by buying you music. At this point, you have a successful music career and making a living doing what you love to do. You will never have to worry about going back to a 9-5 and all is good.