Luckily, I started when they were just pups. Because I discovered something on our recent vacation: The large window of musical influence that I've exerted over my kids all these years has shrunk down to almost nothing.
We take a driving vacation every other year, and in past years, I've been able to dominate the music in the van, mainly under the old "he who drives shall pick the tunes" rule. In order to promote open family communication, and discourage competing noise levels, I've agreed to leave the volume down, and the kids have agreed to stay off the headphones. I've used these opportunities to introduce tons of great artists and albums to the kids.
But I couldn't pull it off this year. All musical hell broke loose.