Classical music, children's folk music, and children's nursery rhymes

Soft background music works best while reading. Just enough to give some relaxing ambiance without distraction. Two of my favorites are The Nutcracker Suite and Rhapsody in Blue

https://www.reddit.com/r/classicalmusic/comments/1k3irzl/children_stories_with_good_music/
https://www.reddit.com/r/books/comments/v4o2hb/songs_when_reading_to_kids/