I hate the repetition of kid's music, so I have never really listened to it with my child. I did try to buy the "not explicit" versions of songs, though, so she wouldn't hear a bunch of F-words and stuff.

My daughter has always been exposed to normal adult music and she really likes a lot of it. The day "enter sandman" came on the radio and she started playing air guitar and yelled, "Metallica!" was one of my proudest moments as a parent. She was maybe 5.

OP, I'm sitting here at work with the itsy bitsy spider stuck in my head because my 18 month old and I sang it probably 15 times this morning. For the love of g*d, do not subject yourself to kid music a minute earlier than you need to. If playing specific music could make your baby a good sleeper, we'd ALL be doing it by now. There's no magic bullet to parenting and any company claiming there is trying to sucker naive FTMs. Don't fall for it! Play whatever music you want and sing to your baby once s/he's here. And congrats!

Thank you all -- such great advice!!!!! I will be buying that book - I've heard some of my mommy friends mention it as well so I just ordered it on Amazon.