There is no "secret" to success in any business. It is a combination of many things - among them: skill, knowledge, hard work, determination and luck - and perhaps in the entertainment industry you could also add "appearance" (which I think falls under luck - some people have the good luck to be good looking).
At some point, if "success" seems to be knocking, an artist will likely need other people to lend additional skills and knowledge (booking agents, a manager, a lawyer, etc.) - as someone else indicated - it is a rare person that can do it all.
In the music industry (music business), you need a certain amount of skill - singing, performing, writing, etc. You also need "people skills" - working with talented people often means working with large egos. You also need knowledge - in particular business knowledge (marketing, finances, etc.) - which can range anywhere from how to get gigs to how to book a studio, etc.
Skills and knowledge can be acquired from any number of sources: on line, libraries, teachers, etc. - improving skills and knowledge is simply a matter of time, effort and dedication.
However, more than any other factor, perhaps determination is the key. You have to be willing to work at your craft every day, take whatever gigs you can to advance yourself - do whatever it takes. Successful people often sleep less, watch TV less and in general waste less time on things that will not make them successful.
While luck may be a factor I have never placed that much faith in luck. There is an old saying to the effect "the harder I work, the luckier I get" - which I believe in. Each of us makes our own luck - in large part by being prepared when an opportunity comes along.
During the last 40 years I've worked with hundreds of musicians - at various levels of success - and I have found the ones who work the hardest, spend the most time and effort and are the most willing to sacrifice other things in life to succeed...........do tend to be the most successful.
