My dad told me about these. The same people have put out albums of lullaby renditions of The Beatles, U2, Coldplay, Radiohead, Metallica, Bob Marley, Led Zeppelin, Niravana, Smashing Pumpkins and a bunch more.
My pops said they were pretty sweet. If anyone's interested to hear samples, they're all on iTunes. Just search "Rockabye Baby!"