My problem with the lullaby is that it's used for very young children (preschoolers and the like).
I must admit that as a preschooler I didn't take much notice of lyrics even when I understood them. Mostly, I didn't understand them or I misinterpreted them. I chose the lullaby for House to play because I thought it might have been something his mother or his oma played for him on the piano when he was a child, a subconscious association with happy bedtimes which makes him choose this piece to play on his rediscovered instrument. (The first hymn is a knee-jerk reaction to the vicodin - you as a socialist surely know all about the parallels between religion and opiates, and I'm pretty sure that House shares that opinion [as do I, to some extent] - the second merely a means of messing with Wilson's head.)