BryanV,
You should have your outdoor speakers repeat the message to "turn your radio to station xx.x to hear the music." Maybe they would get the hint. lol.
My neighbor directly across the street in plain view can see one of my signs. One night while working on an issue she came out and said the lights look nice. The next night while working on same issue, she made a point to stop and say that she didn't know that the lights went to music. It took her granddaughter to tell her when both of them were going to grandma’s house and the granddaughter seen the sign from the car and she was so excited and couldn’t wait to see the lights at night. She is a nice neighbor but she has a few bricks shy from a full load.
Dan