Living the questions: that's a philosophical concept – or at least, suggestion – which shows up in many ways people have tried to understand life across the centuries. Music is, or can be, a part of living with and through questions, both as companion and as source of ideas.

Often, in this series of stories, the idea of questions has come up. As unexpected changes continue in the world's political and social spheres, here are four more songs which have good questions at their heart.