Music is a very powerful mood influencer. There is more and more research emerging about the power of music. I have found calm relaxing music to be a big help with my children at bed time. It gives the mind something to focus on. So if your child is having trouble letting go of worries, or their imagination is going wild and not for their good, then calm relaxing music can work wonders.
We play relaxing piano play-lists from spotify. But you may need to experiment. Your child may prefer nature sounds (ocean, birds, rain etc.), or white noise.
When my children are struggling I’ll put the music on and ask them to focus on the music. I have found this to work pretty much every time. Now, my children will often just call out “piano music please!” Yes! they are self regulating their emotions!
I used to play piano music every night, when my son was really struggling with fears. Now, I just play it when I identify they need it or when they request it.