I agree with rock, balz and tom.

I think the discussion on type of music has no business in this thread. Taste in music is personal, what you find enjoyable others may find disagreeable. I am sure the guy blasting out mariachi and narco corridos in the parking lot at Grant's Grove this past summer would not enjoy the music I like. His taste in music didn't make has actions any more or less reprehensible.

In the end when you are moving, you create a lot of ambient background noise. In order for you to put out music so the guy at the front of the line can hear means someone enjoying a quiet picnic can hear it from a long way off.

I say either bluetooth everything or let everyone carry their own I-whatever.