Becoming a blues man requires life experience; a person cannot simply make a conscious decision to become one. But if someone has experienced grief or misfortune and knows how to play rhythmically inclined music, there's a chance that he can become a blues man. Blues men usually either play piano, guitar or harmonica, and sing. A person of any race can become a blues man, but the music's history is inherent to African-American culture.
Get the Blues
The blues is a paradoxical art form, because it is a response to an experience of heartbreak or sorrow. Nobody really wants to get the blues in the first place, but if they do, playing blues music will help make the heartbreak or sorrow lighten. So unfortunately, the first thing that must happen if one wants to become a blues man is he must experience something painful. A famous blues man once said, "Bad luck and trouble are always present in the Blues, and always the result of others, pressing upon unfortunate and down trodden poor souls, yearning to be free from life's' troubles."
If the man is not yet a learned musician, he cannot play the blues. But luckily, most blues music is repetitive and easy. Twelve-bar blues can be played by any blues man. As with any music, it takes hours and hours of practice to become proficient. If you want to be called a "blues man," it will require years of work and recognition. The term "blues man" cannot be self-appointed.
Once you've become proficient in whatever instrument(s) you've decided to play, perform your songs. There are tons of blues songs already written that you can play, but a true blues man will tell his own stories. Again, this will probably take years of practice. But if you stick with it, you'll eventually write blues songs that will make an audience feel as blue as the day you did when you decided to take up the art.
Hang out with real blues men if you can. Go to blues bars and sit and talk with the guys after they've played a set. Get their advice.
Listen to the best blues music ever made. B. B. King, Muddy Waters, John Lee Hooker, Leadbelly and Howlin Wolf should be a constant source of inspiration and company.
If you're not sincere about the blues, do not attempt it. Blues is all about feeling and emotion, and audiences will be able to spot an amateur easily.