I tend to sing to Celeste both as part of play and as part of calming/soothing. Evelin tends to sing only during play, so she's expressed concern that my soothing singing is having the opposite effect. Whether that's it or not, sleep is fleeting for Celeste these days: 30–45 minute naps and what seems like way too many awakenings during the night. I'm sure it's just a phase and she'll be a sleep champ in a few years or something, but in the mean time I'm laying off the lullabies.
Of course, my choice of lullabies has always been eclectic. The Smiths, "Cemetry Gates;" Billy Bragg, "A New England;" Billy Idol, "Dancin' With Myself" (with new lyrics to make it "Dancin' With Celeste"); Johnny Cash, "Folsom Prison Blues;" "16 Tons;" "Joe Hill;" or something, along with nonsense tunes that play with Celeste's name ("Celeste ... ial Seasonings is a tea that mommy drinks; Celeste ... ial mechanicals explains the motion of the stars; Celeste ... ial navigation requires an astrolabe; usw.") or that work in the phrase "fais-do-do."
Evelin is fond of the Sandra Boyton CDs, but I can never remember the words ...
Of course, the worst part of the singing is when you find yourself humming "Never Smile at a Crocodile" or, even worse, "The Wheels on the Bus" during the workday.