First of all, Mr Paperback Writer, allow me to congratulate you for probably being the number one poster of thoughtful and original threads here. I almost always look forward to your questions, and I almost always make a point of responding to them. A tip of the hat to you.
Now on the the question at hand. I think, like John Lennon, or Bono, if as well as making quality music, that people want to hear, you have some political message (or any message of importance for that matter), it is well within your right to have as many people hear it as possible. You absolutely take the risk of people not only not listening to you, but maybe even stop listening to your music. But thats a risk Lennon and Bono took. that takes balls, if you ask me.
When I was in high school, I saw Stevie Ray Vaughan live in concert around 20 different times. He was a blues player who obviously went to the Jimi Hendrix school of blues. He evidently lived hard, nearly died due to drugs and alcohol. And every time I saw him, EVERY TIME, during what I consider do be his greatest song, he would pause the music, and give the audience a sermon (nearly 15 minutes long) about how important to live cleanly. Without booze and drugs. I respected his message. I believed he believed in what he was saying. I even thought what he was saying was right. However, truthfully, I paid to see a rock-n-blues concert, so I talked with my friends during this part. I tuned him out.
If a musician tries to improve the world by saying something of substance, if he really has an opportunity to have his voice heard, he should say what he has to say. But he does take the risk of not being heard, or being ignored, or worse yet, there being a backlash against him. But having something to say, and having the chance to be heard, and not saying it, THAT is a crime.
I want to tell her that I love her a lot, but I got to get a belly full of wine.