Elaine is 100% correct. Musicians have to maintain their own integrity and "ministry" when it comes to your craft. A musician, bottom line, is an accompliment to the words that are being brought forth. Whatever words they are, the music only supplies the mood, tone, and overall ambience. So, if unless the singer is singing "Lord, Make Me Over", it would not make sense for a gospel musician to be in a club setting.
Now, it is only fair that I say this:
There are musicians out there that are simply, "musicians". They will play anything and everything that they can because of the craft that they have developed. There are quite a few musicians that LOVE gospel music, not because they listen to the ministry to apply to their life, but because it simply sounds nice. (Yes, you can listen to gospel music because it sounds nice.) So, actually, it would sound silly to tell someone that plays gospel music they are wrong for playing in a club when they don't consider THEMSELVES as a devoted part of a particular ministry.
I believe this last statement had to be said so the people of GOD are not easily bamboozled =o)