It’s something that all individuals and societies have done for millions of years. But why do we sing? Today singing is a way of bringing people together, expressing joy, sadness and almost every emotion. Is there an evolutionary reason why and how humans developed the complex vocal structures involved in singing?

Mike Williams talks to biologists, voice coaches and vocalists to find out.

(Image of Chinese women singing in a choir in Chongqing, China. Credit Getty Images)