SAY YES! Say no.
In some ways musicians are champions of optimism. No matter how bad or poorly paid a gig may be, there is always the hope, "Well, it might lead to something better. Who knows." In one of my busier stretches as a sideman I remember channeling this hope as I drove off from a gig at a pumpkin festival where we had played jazz standards to straw bales and a man dressed in a giant pumpkin suit. As farmland flew past, I reached for optimism amid the roar of interstate traffic.
One time a teacher told me to "take every gig, no matter what. Play as much as you can, anywhere and everywhere." I took that advice to heart and lived by that motto for years until several overuse injuries forced me to idle down. I could't play music for awhile. It was an odd feeling that fused frustration, financial stress, a sense of mortality, and perceived personal failure into fertile ground for introspection.
As a default, many musicians tend to say yes to every opportunity. Why? Any given show, project, or gig might lead to something else. This is hard to argue, as action undoubtedly generates potential in the world. But then you spend your time doing things that "might lead to something" while you could be doing other things that might better lead to something. The target is hazy. Compulsive action at work. Confusing eh? Other reasons musicians always say yes: they just love to play, no matter what; they need the money, no matter how meager; they believe it best for chops to perform all the time. It is hard to say whether any one of these statements is true or false, each being so personal.
There is a sense of desperation in accepting every opportunity, in being unable to say no. Is it a larger cultural value that fosters relentless, compulsive action as the inevitable means of progressing from rags to riches? Is self-esteem (or lack thereof) also at play? It takes work to learn how to say no. And confidence. And perhaps a more open mind about how things can come together in terms of a career. I am not saying that a musician should not perform as much as he/she sees fit, but I am saying that the default "yes" attitude has a few significant blindsides. More may not always mean better.