Rockabye Baby! solves this problem beautifully. This series of music albums features lullaby renditions of favorite artists such as The Cure, U2, Bob Marley, and The Beatles. Calming instruments like the glockenspiel and xylophone are used in place of the drums. The result is an album that's gentle enough for a baby, yet enjoyable for the parents as well.
I was excited to learn that one of the albums available was the lullaby renditions of Bjork. I quite like her music, but unfortunately I am not a fan of her voice (sorry to anybody that is.) So an album that features her music without the voice? I'm completely sold. After listening to it, I am thoroughly impressed. It manages to capture the true essence of Bjork with each song, yet at the same time the album is a work of art in its own right. In other words, even if you had never heard a Bjork song before this album is still great to listen to. Best of all, my son can drift off to sleep while listening to it.
Check out the full list of albums available here and "rock" your baby to sleep!