When I drove my delivery truck I would designate certain days of the week for certain kinds of music, pretty much at random, but I would stick with it the whole day.
One day might be "Bay Area Monday", "Weird Al Wednesday" or "80's Thursday"...
Every now and then sales guys would do ride-a-longs with drivers. One guy was a hipster named Aaron rode with me on a "Metal Friday". About half way threw the day he commented that the Anthrax song "I'm the Man" was "The worst music I've ever heard, ever." And mentioned several times that he didn't understand why we couldn't listen to something else, my only answer was "Well, its Metal Friday, what do you suggest?" and he just sat there and stewed...lol, it was pretty funny.
He's a moron, he also said that he wanted to buy a "really, really nice watch." When I asked what kind or how much he wanted to spend and he said "really expensive, something like $200-$300."