Soft soothing classical music or 'spa' music is far far the best to temp a child off to sleep.
https://www.youtube.com/watch?v=xQ6xgDI7Whc
or
https://www.youtube.com/watch?v=luRkeDCoxZ4
What are some good songs to play to help a toddler get to sleep?
There's a longer version and this is a great cartoon any youngster would love !