When I was getting ready to go to Brigham Young University, a year early, my parents assured me that everyone was popular in college, so I signed up for the honors dorm. Which was full of nerds. My roommate was supernice, but he was getting up at 6AM before orientation even started, because he knew that's what he was going to have to do when he became a missionary, so.
Also, he'd walk around with a Walkman on, singing some headbanger song, but when it'd come to the line, "making love to every woman I meet," he'd change it to "making CAKE for every woman I meet." I can't figure out what that song was, either; it's like it's playing, muffled, a room away in my head. I lasted about three days and then moved to the normal dorm with a bunch of guys from Southern California, and it all worked out. Anyway.
Point is, I used to sing the Red Hot Chili Peppers' "Under The Bridge" to the kid to get her back to sleep. Until she started understanding the words, which seemed pretty heavy for a toddler.
And I sang Johnny Cash's cover of Trent Reznor's "Hurt" to K2 until I hit the same comprehension threshold. Now I just sing it as a joke, but with changes like, "I burped myself today. To see if I still smell" in my best, late Cash growl. They're rarely as amused as I am.
Which makes me wonder if anyone else does this, besides me--and, of course, Adam Buxton.
I used to sing "The Needle and the Damage Done" to our now 3-year old to get him to sleep, but stopped when our 5-yr old started asking questions (she got heavy doses of "Old Man" as an infant). Now we just sing along every once in a while to "Needle" while in the car, which is a distracting enough environment to avoid long discussions of intravenous drug use. Phew.
One of my fondest elementary school memories is music time in first grade. Mr. Hunt used to sing and play guitar for us. Best part: singing The Gambler, where the namesake of the song took "a taste of my Kool-aid" then "he bummed a Twinkie, and offered me a bite." Not sure it's a much healthier option. Age appropriate, yes, but I still wouldn't give my kids that crap.
I remember a couple of years ago on a plane from Italy to France, my one year old was freaking out. To calm her down I sang her favorite lullaby, which was Sunday Bloody Sunday slowed down. She went to sleep, but I got some pretty funny sideways glances from other passengers. Anyway, yeah, she's too old for that one now.
The Cure's "Lullaby" was what put our first to sleep. I didn't sing the lyrics, but did a little "da-da-dee-dum" while keeping beat with a gentle pat on her back. The tempo is pretty close to a resting heartbeat. Our second got "Elegia" from New Order. No lyrics for me to mess up.
"Margaritaville" always seemed to work pretty well, but I got sick of singing it. I do remember some nights when I was so tired, I would just sing whatever the hell I could remember the words to. I actually sang "Enter Sandman" once in such a state.