Most of us live our lives without contact with the homeless and marginalised in society. We might pass each other in the street, or throw a couple of coins in the hat. But the Auckland Street Choir is that rare thing: a project where people from profoundly different worlds work together. Auckland Street Choir founder and musical director Rohan MacMahon and some of the choir's members, including Rawiri Sears-Ngatai, come into the RNZ studio.