This month sees the release of my 20th picture book, Levi’s Gift, which captures the beginning of a cross-generational, cross-cultural friendship between an old man and a young girl. It’s also about the healing power of music.

I’ve always had a soft spot for stories about friendships between children and old people, and although I’ve never played any musical instrument, stories involving music and especially violins have often moved me too.

So it’s no surprise that when I saw the documentary Jo...