Loud music. Where?

You know how you're on the sidewalk and you hear loud music? You look around, searching for the source. All I saw this fine March day were two guys on bicycles. Obviously, the music was moving. Wish I tell you what was playing, but I didn't recognize it.


I watched them go east on the street and spied the jam box--is it too small to be a boom box?--that one of them attached to his back! He's got it strapped to the top of his backpack. Creative problem solving. He's got his safety red light on his backpack, too.