The other week I was making a delivery at a baby's / children's furniture store and was getting a signature by the front desk. I happen to notice they have a small CD display, and I recognized one cover from Coldplay. A closer look reveals that it, and all the CD's in the display, are lullaby versions of these bands. It was then I realized that the song I was hearing was the lullaby version of Stairway to Heaven. I ended up buying the Radiohead version then, and ordering U2, which I've since gotten but haven't listened to yet.
They make lullaby versions of ...
Queens of the Stone Age
Nine Inch Nails (wonder what Closer sounds like?)