Back in high school, I had a few rules about the car stereo: No Ozzy Osbourne. No AC/DC. If they came on the radio, I'd change the station no matter how my passengers felt. I sucked it up and willingly went to an AC/DC concert years later as a favor to a friend; she wanted to photograph them for the magazine we both worked for, so I agreed to review the show, but that still didn't violate the car rule.

Now I've got a toddler son who is both crazy about trains and will request that I sing even the shortest snippet of a song again and again. When he was enthusing about a train when we were driving recently, I sang the one-line chorus of Ozzy's "Crazy Train," which I had to fake in parts, "We're going (mumble mumble) rails of the crazy train." He demanded, "Again," over and over. I obliged a few times since he is irresistibly charming. Then I tried switching to "I've Been Working on the Railroad," but he responded, "Crazy Train," and continued to request it. So I broke down and borrowed an Ozzy CD from the library so I could play him the whole song, which I've already done twice, much to his delight.

I've decided to use "Crazy Train" as the starting point for a mix CD for him, "Train Tracks." I'll fill it with lots of songs about trains, especially ones that are not obviously appropriate for a toddler, like "5:15" by the Who and Love & Rockets' "Kundalini Express." I'm just following the High Fidelity definition of true selfless love: when you make a mix of songs the other person will like instead of what you think they should like, although I'll still skip "Casey Jones" by the Grateful Dead.