I just read an article on my apple news feed. This is a bit outside the box, but here goes. A father was remembering how he used to get his child to go to sleep when she was a baby. He found that rubbing her back 100 times , slowly and rhythmically, I imagine was very effective and it made him relax as well. Massage releases endorphins, so this makes sense. There is a lot of massage music on You Tube.