I see I'll likely be the only one to come forth and say this but...

I didn't sing songs with what I considered inappropriate subject matter to my babies (four of them). I did sing some non-violent, non-"boozy" (as Mudlark put it), dreamy and comforting sounding folk songs (there are plenty which do the job well), some popular songs, but the ones my kids preferred were Christmas carols (lots of baby sleeping songs there), "What Child is This/Greensleeves" tune for lots of made up lullabies with the child's name in it, and one our kids favorite, a contemporary lullaby called "Pirate Ships" by Wendy Waldman.

I really am opposed to singing violent songs of any ilk to children, just as I am opposed to singing them drinking songs, songs about sex, etc.